You can edit almost every page by Creating an account. Otherwise, see the FAQ.

Module:Wikidata

Uit EverybodyWiki Bios & Wiki
Ga naar:navigatie, zoeken

Documentatie Module:Wikidata/doc

Testwaarden Module:Wikidata[bewerken]

PS: id= wordt normaal niet gebruikt. Het dient hier om met behulp van Arbitrary access waarden van andere artikelen te kunnen testen.

Command Expected result Pass/Fail Result
Claim, Images
{{#invoke:Wikidata|claim|p41|id=Q727}} Flag of Amsterdam.svg fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
Claim, Strings
{{#invoke:Wikidata|claim|p1477|id=Q5598}} Rembrandt Harmenszoon van Rijn fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
Claim, Monolingualtext
TBD
Claim, Items
{{#invoke:Wikidata|claim|p106|id=Q5598}} kunstschilder fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p106|parameter=link|id=Q5598}} kunstschilder fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p106|parameter=count|id=Q5598}} 3 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p106|parameter=link|list=, |id=Q5598}} kunstschilder, tekenaar, prentgraveur fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
Claim, Date / Time
{{#invoke:Wikidata|claim|p569|id=Q5598}} 15 juli 1606 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p837|id=Q34812}} 1 januari fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p582|id=Q12554}} 1519 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p580|id=Q1}} 13798 mln. jaar geleden fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
Claim, Coordinates
{{#invoke:Wikidata|claim|p625|id=Q727}} 52.383333333333/4.9 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p625|parameter=latitude|id=Q727}} 52.383333333333 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p625|parameter=longitude|id=Q727}} 4.9 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
Claim, Quantities
{{#invoke:Wikidata|claim|p1082|id=Q727}} 825080 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|p1108|id=Q560}} 4,5 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
Claim, URL's
{{#invoke:Wikidata|claim|p856|id=Q727}} https://www.amsterdam.nl fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
Claim, Qualifiers, References etc.
{{#invoke:Wikidata|claim|P1082|qualifier=P585|id=Q727}} 31 maart 2015 fail Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|claim|P1566|references=ja|id=Q727}} 2759794[1] Check, probably OK Luafout op regel 364: attempt to index field 'wikibase' (a nil value)
  1. geïmporteerd uit: GeoNames
  2. geïmporteerd uit: GeoNames
getValue
TBD
descriptionIn
{{#invoke:Wikidata|descriptionIn|ru|Q5598}} нидерландский художник, рисовальщик и гравёр fail Luafout op regel 90: attempt to index field 'wikibase' (a nil value)
labelIn
{{#invoke:Wikidata|labelIn|ru|Q5598}} Рембрандт fail Luafout op regel 97: attempt to index field 'wikibase' (a nil value)
labelOf
{{#invoke:Wikidata|labelOf|Q5598}} Rembrandt fail Luafout op regel 435: attempt to index field 'wikibase' (a nil value)
pageId
{{#invoke:Wikidata|pageId}} Q12069631 or blank fail Luafout op regel 422: attempt to index field 'wikibase' (a nil value)
sitelinkOf
{{#invoke:Wikidata|sitelinkOf|Q5598}} Rembrandt van Rijn fail Luafout op regel 447: attempt to index field 'wikibase' (a nil value)
badges
{{#invoke:Wikidata|badges|enwiki|Q5598}} Q17437798
(=goed artikel)
fail Luafout op regel 454: attempt to index field 'wikibase' (a nil value)
getSiteLink
Gebruik: [[en:{{#invoke:Wikidata|getSiteLink|enwiki}}|Module:Wikidata op de Engelstalige Wikipedia]]
{{#invoke:Wikidata|getSiteLink|commonswiki|id=Q60045}} Albert Speer fail Luafout op regel 75: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|getSiteLink|enwikivoyage|id=Q60045}} (geen uitvoer) fail Luafout op regel 75: attempt to index field 'wikibase' (a nil value)
{{#invoke:Wikidata|getSiteLink|nietbestaandewiki|id=Q60045}} (geen uitvoer) fail Luafout op regel 75: attempt to index field 'wikibase' (a nil value)

-- module local variables
local wiki = 
{
	langcode = mw.language.getContentLanguage().code
}

-- internationalisation
local i18n = {
	["errors"] = {
		["property-not-found"] = "Eigenschap niet gevonden.",
		["entity-not-found"] = "Wikidata-entiteit niet gevonden.",
		["unknown-claim-type"] = "Onbekend statementtype.",
		["unknown-snak-type"] = "Onbekend snaktype.",
		["unknown-datavalue-type"] = "Onbekend gegevenstype.",
		["unknown-entity-type"] = "Onbekend entiteitstype.",
		["qualifier-not-found"] = "Kwalificatie niet gevonden.",
		["site-not-found"] = "Wikimedia-project niet gevonden."
	},
	["somevalue"] = "Onbekende waarde",
	["novalue"] = "Geen waarde",
	["datetime"] =
	{
		-- $1 is a placeholder for the actual number
		[0] = "$1 mld. jaar",		-- precision: billion years
		[1] = "$100 mln. jaar",		-- precision: hundred million years
		[2] = "$10 mln. jaar",		-- precision: ten million years
		[3] = "$1 mln. jaar",		-- precision: million years
		[4] = "$100.000 jaar",		-- precision: hundred thousand years
		[5] = "$10.000 jaar",		-- precision: ten thousand years
		[6] = "$1e millennium",		-- precision: millennium
		[7] = "$1e eeuw",			-- precision: century
		[8] = "jaren $1",			-- precision: decade
		-- the following use the format of #time parser function
		[9] = "Y",					-- precision: year
		[10] = "F Y",				-- precision: month
		[11] = "j F Y",				-- precision: day
		[12] = 'j F Y, G "uur"',	-- precision: hour
		[13] = "j F Y G:i",			-- precision: minute
		[14] = "j F Y G:i:s",		-- precision: second
		["beforenow"] = "$1 geleden",	-- how to format negative numbers for precisions 0 to 5
		["afternow"] = "over $1",		-- how to format positive numbers for precisions 0 to 5
		["bc"] = '$1 "v.Chr."',		-- how print negative years
		["ad"] = "$1"				-- how print positive years
	},
	["monolingualtext"] = '<span lang="%language">%text</span>'
}

local p = { }

local function printError(code)
	return '<span class="error">' .. i18n.errors[code] .. '</span>'
end

-- the "qualifiers" and "snaks" field have a respective "qualifiers-order" and "snaks-order" field
-- use these as the second parameter and this function instead of the built-in "pairs" function
-- to iterate over all qualifiers and snaks in the intended order.
local function orderedpairs(array, order)
	if not order then return pairs(array) end

	-- return iterator function
	local i = 0
	return function()
		i = i + 1
		if order[i] then
			return order[i], array[order[i]]
		end
	end
end

-- getting sitelink of a given wiki
-- source: https://en.wikipedia.org/w/index.php?title=Module:Wikidata&oldid=757775054 line 1102
function p.getSiteLink(frame)
	local siteId = frame.args[1]
	local wikidataId = frame.args["id"]
	local entity = mw.wikibase.getEntity( wikidataId )
	if not entity then
		return
	end
	local link = entity:getSitelink( siteId )
	if not link then
		return
	end
	return link
end

function p.descriptionIn(frame)
	local langcode = frame.args[1]
	local id = frame.args[2]
	-- return description of a Wikidata entity in the given language or the default language of this Wikipedia site
	return mw.wikibase.getEntityObject(id).descriptions[langcode or wiki.langcode].value
end

function p.labelIn(frame)
	local langcode = frame.args[1]
	local id = frame.args[2]
	-- return label of a Wikidata entity in the given language or the default language of this Wikipedia site
	return mw.wikibase.getEntityObject(id).labels[langcode or wiki.langcode].value
end

local function printDatavalueCoordinate(data, parameter)
	-- data fields: latitude [double], longitude [double], altitude [double], precision [double], globe [wikidata URI, usually http://www.wikidata.org/entity/Q2 [earth]]
	if parameter then
		if parameter == "globe" then data.globe = mw.ustring.match(data.globe, "Q%d+") end -- extract entity id from the globe URI
		return data[parameter]
	else
		return data.latitude .. "/" .. data.longitude -- combine latitude and longitude, which can be decomposed using the #titleparts wiki function
	end
end

local function printDatavalueQuantity(data, parameter)
	-- data fields: amount [number], unit [string], upperBound [number], lowerBound [number]
	if parameter then
		return data[parameter]
	else
		return string.gsub(tonumber(data.amount),"%.",",") -- nl: replace dot decimal separator by comma decimal separator
	end
end

-- precision: 0 - billion years, 1 - hundred million years, ..., 6 - millenia, 7 - century, 8 - decade, 9 - year, 10 - month, 11 - day, 12 - hour, 13 - minute, 14 - second
local function normalizeDate(date)
	date = mw.text.trim(date, "+")
	-- extract year
	local yearstr = mw.ustring.match(date, "^\-?%d+")
	local year = tonumber(yearstr)
	-- remove leading zeros of year
	return year .. mw.ustring.sub(date, #yearstr + 1), year
end

function formatDate(date, precision, timezone, calendarmodel)
	precision = precision or 11
	date, year = normalizeDate(date)
	if year == 0 and precision <= 9 then return "" end

	-- precision is 10000 years or more
	if precision <= 5 then
		local factor = 10 ^ ((5 - precision) + 4)
		local y2 = math.ceil(math.abs(year) / factor)
		local relative = mw.ustring.gsub(i18n.datetime[precision], "$1", tostring(y2))
		if year < 0 then
			relative = mw.ustring.gsub(i18n.datetime.beforenow, "$1", relative)
		else
			relative = mw.ustring.gsub(i18n.datetime.afternow, "$1", relative)
		end
		return relative
	end

	-- precision is decades, centuries and millenia
	local era
	if precision == 6 then era = mw.ustring.gsub(i18n.datetime[6], "$1", tostring(math.floor((math.abs(year) - 1) / 1000) + 1)) end
	if precision == 7 then era = mw.ustring.gsub(i18n.datetime[7], "$1", tostring(math.floor((math.abs(year) - 1) / 100) + 1)) end
	if precision == 8 then era = mw.ustring.gsub(i18n.datetime[8], "$1", tostring(math.floor(math.abs(year) / 10) * 10)) end
	if era then
		if year < 0 then era = mw.ustring.gsub(mw.ustring.gsub(i18n.datetime.bc, '"', ""), "$1", era)
		elseif year > 0 then era = mw.ustring.gsub(mw.ustring.gsub(i18n.datetime.ad, '"', ""), "$1", era) end
		return era
	end

	-- precision is year
	if precision == 9 then
		return year
	end

	-- precision is less than years
	if precision > 9 then
		--[[ the following code replaces the UTC suffix with the given negated timezone to convert the global time to the given local time
		timezone = tonumber(timezone)
		if timezone and timezone ~= 0 then
			timezone = -timezone
			timezone = string.format("%.2d%.2d", timezone / 60, timezone % 60)
			if timezone[1] ~= '-' then timezone = "+" .. timezone end
			date = mw.text.trim(date, "Z") .. " " .. timezone
		end
		]]--

		local formatstr = i18n.datetime[precision]
		if year == 0 then formatstr = mw.ustring.gsub(formatstr, i18n.datetime[9], "")
		elseif year < 0 then
			-- Mediawiki formatDate doesn't support negative years
			date = mw.ustring.sub(date, 2)
			formatstr = mw.ustring.gsub(formatstr, i18n.datetime[9], mw.ustring.gsub(i18n.datetime.bc, "$1", i18n.datetime[9]))
		elseif year > 0 and i18n.datetime.ad ~= "$1" then
			formatstr = mw.ustring.gsub(formatstr, i18n.datetime[9], mw.ustring.gsub(i18n.datetime.ad, "$1", i18n.datetime[9]))
		end
		if (mw.ustring.find(calendarmodel, 'Q1985786', 1, true)) and year > 1582 then
			return mw.language.new(wiki.langcode):formatDate(formatstr, date) .. '<sup>&thinsp;[[Juliaanse kalender|jul.]]</sup>'
		else
			return mw.language.new(wiki.langcode):formatDate(formatstr, date)
		end
	end
end

local function formatDateLink(time, precision, calendarmodel)
	precision = precision or 11
	local year, m, d = mw.ustring.match( time, "(%-?%d+)%-(%d+)%-(%d+)T" )
	local maanden = {'januari', 'februari', 'maart', 'april', 'mei', 'juni', 'juli', 'augustus', 'september', 'oktober', 'november', 'december'}
	m = tonumber(m)
	d = tonumber(d)
	year = tonumber(year)

	-- precision is decades, centuries and millenia
	local era
	if precision == 6 then era = mw.ustring.gsub(i18n.datetime[6], "$1", tostring(math.floor((math.abs(year) - 1) / 1000) + 1)) end
	if precision == 7 then era = mw.ustring.gsub(i18n.datetime[7], "$1", tostring(math.floor((math.abs(year) - 1) / 100) + 1)) end
	if precision == 8 then era = mw.ustring.gsub(i18n.datetime[8], "$1", tostring(math.floor(math.abs(year) / 10) * 10)) end
	if era then
		if year < 0 then era = mw.ustring.gsub(mw.ustring.gsub(i18n.datetime.bc, '"', ""), "$1", era)
		elseif year > 0 then era = mw.ustring.gsub(mw.ustring.gsub(i18n.datetime.ad, '"', ""), "$1", era) end
		return era
	end

	if precision == 9 then
		return '[[' .. year .. ']]'
	end

	if precision == 10 then
		if m == 8 then
			return '[[Augustus (maand)|augustus]] [[' .. year .. ']]'
		else
			return '[[' .. maanden[m] .. ']] [[' .. year .. ']]'
		end
	end

	if precision > 10 then
		if (mw.ustring.find(calendarmodel, 'Q1985786', 1, true)) and year > 1582 then
			return d .. ' ' .. maanden[m] .. ' ' .. year .. '<sup>&thinsp;[[Juliaanse kalender|jul.]]</sup>'
		else
			return '[[' .. d .. ' ' .. maanden[m] .. ']] [[' .. year .. ']]'
		end
	end
end

local function printDatavalueTime(data, parameter)
	-- data fields: time [ISO 8601 time], timezone [int in minutes], before [int], after [int], precision [int], calendarmodel [wikidata URI]
	--   precision: 0 - billion years, 1 - hundred million years, ..., 6 - millenia, 7 - century, 8 - decade, 9 - year, 10 - month, 11 - day, 12 - hour, 13 - minute, 14 - second
	--   calendarmodel: e.g. http://www.wikidata.org/entity/Q1985727 for the proleptic Gregorian calendar or http://www.wikidata.org/wiki/Q11184 for the Julian calendar]
	if parameter then
		if parameter == "calendarmodel" then data.calendarmodel = mw.ustring.match(data.calendarmodel, "Q%d+") -- extract entity id from the calendar model URI
		elseif parameter == "time" then data.time = normalizeDate(data.time) end
		if parameter == "link" then
			return formatDateLink(data.time, data.precision, data.calendarmodel)
		end
		return data[parameter]
	else
		return formatDate(data.time, data.precision, data.timezone, data.calendarmodel)
	end
end

local function printDatavalueEntity(data, parameter)
	-- data fields: entity-type [string], numeric-id [int, Wikidata id]
	local id = "Q" .. data["numeric-id"]
	if parameter then
		if parameter == "link" then
			return "[[" .. (mw.wikibase.sitelink(id) or (":d:" .. id)) .. "|" .. (mw.wikibase.label(id) or id) .. "]]"
		else
			return data[parameter]
		end
	else
		if data["entity-type"] == "item" then return mw.wikibase.label("Q" .. data["numeric-id"]) or id else printError("unknown-entity-type") end
	end
end

local function printDatavalueMonolingualText(data, parameter)
	-- data fields: language [string], text [string]
	if parameter then
		return data[parameter]
	else
		return mw.ustring.gsub(mw.ustring.gsub(i18n.monolingualtext, "%%language", data["language"]), "%%text", data["text"])
	end
end

function findClaims(entity, property)
	if not property or not entity or not entity.claims then return end

	if mw.ustring.match(property, "^P%d+$") then
		-- if the property is given by an id (P..) access the claim list by this id
		return entity.claims[property]
	else
		property = mw.wikibase.resolvePropertyId(property)
		if not property then return end

		return entity.claims[property]
	end
end

function getSnakValue(snak, parameter)
	-- snaks have three types: "novalue" for null/nil, "somevalue" for not null/not nil, or "value" for actual data
	if snak.snaktype == "novalue" then return i18n["novalue"]
	elseif snak.snaktype == "somevalue" then return i18n["somevalue"]
	elseif snak.snaktype ~= "value" then return nil, printError("unknown-snak-type")
	end

	-- call the respective snak parser
	if snak.datavalue.type == "string" then return snak.datavalue.value
	elseif snak.datavalue.type == "globecoordinate" then return printDatavalueCoordinate(snak.datavalue.value, parameter)
	elseif snak.datavalue.type == "quantity" then return printDatavalueQuantity(snak.datavalue.value, parameter)
	elseif snak.datavalue.type == "time" then return printDatavalueTime(snak.datavalue.value, parameter)
	elseif snak.datavalue.type == "wikibase-entityid" then return printDatavalueEntity(snak.datavalue.value, parameter)
	elseif snak.datavalue.type == "monolingualtext" then return printDatavalueMonolingualText(snak.datavalue.value, parameter)
	else return nil, printError("unknown-datavalue-type")
	end
end

local function getQualifierSnak(claim, qualifierId)
	-- a "snak" is Wikidata terminology for a typed key/value pair
	-- a claim consists of a main snak holding the main information of this claim,
	-- as well as a list of attribute snaks and a list of references snaks
	if qualifierId then
		-- search the attribute snak with the given qualifier as key
		if claim.qualifiers then
			local qualifier = claim.qualifiers[qualifierId]
			if qualifier then return qualifier[1] end
		end
		return nil, printError("qualifier-not-found")
	else
		-- otherwise return the main snak
		return claim.mainsnak
	end
end

local function getValueOfClaim(claim, qualifierId, parameter)
	local error
	local snak
	snak, error = getQualifierSnak(claim, qualifierId)
	if snak then
		return getSnakValue(snak, parameter)
	else
		return nil, error
	end
end

local function getReferences(frame, claim)
	local result = ""
	-- traverse through all references
	for ref in pairs(claim.references or {}) do
		local refparts
		-- traverse through all parts of the current reference
		for snakkey, snakval in orderedpairs(claim.references[ref].snaks or {}, claim.references[ref]["snaks-order"]) do
			if refparts then refparts = refparts .. ", " else refparts = "" end
			-- output the label of the property of the reference part, e.g. "imported from" for P143
			refparts = refparts .. tostring(mw.wikibase.label(snakkey)) .. ": "
			-- output all values of this reference part, e.g. "German Wikipedia" and "English Wikipedia" if the referenced claim was imported from both sites
			for snakidx = 1, #snakval do
				if snakidx > 1 then refparts = refparts .. ", " end
				refparts = refparts .. getSnakValue(snakval[snakidx])
			end
		end
		if refparts then result = result .. frame:extensionTag("ref", refparts) end
	end
	return result
end

function p.claim(frame)
	local property = frame.args[1] or ""
	local id = frame.args["id"]
	local qualifierId = frame.args["qualifier"]
	local parameter = frame.args["parameter"]
	local list = frame.args["list"]
	local references = frame.args["references"]
	local showerrors = frame.args["showerrors"]
	local default = frame.args["default"]
	if default then showerrors = nil end

	-- get wikidata entity
	local entity = mw.wikibase.getEntityObject(id)
	if not entity then
		if showerrors then return printError("entity-not-found") else return default end
	end
	-- fetch the first claim of satisfying the given property
	local claims = findClaims(entity, property)
	if not claims or not claims[1] then
		if showerrors then return printError("property-not-found") else return default end
	end

	-- get initial sort indices
	local sortindices = {}
	for idx in pairs(claims) do
		sortindices[#sortindices + 1] = idx
	end
	-- sort by claim rank
	local comparator = function(a, b)
		local rankmap = { deprecated = 2, normal = 1, preferred = 0 }
		local ranka = rankmap[claims[a].rank or "normal"] .. string.format("%08d", a)
		local rankb = rankmap[claims[b].rank or "normal"] .. string.format("%08d", b)
		return ranka < rankb
	end
	table.sort(sortindices, comparator)

	local result
	local error
	if list then
		local value
		-- iterate over all elements and return their value (if existing)
		result = {}
		for idx in pairs(claims) do
			local claim = claims[sortindices[idx]]
			value, error = getValueOfClaim(claim, qualifierId, parameter)
			if not value and showerrors then value = error end
			if value and references then value = value .. getReferences(frame, claim) end
			result[#result + 1] = value
		end
		result = table.concat(result, list)
	elseif parameter == "count" then
		result = #claims
	else
		-- return first element
		local claim = claims[sortindices[1]]
		result, error = getValueOfClaim(claim, qualifierId, parameter)
		if result and references then result = result .. getReferences(frame, claim) end
	end

	if result then return result else
		if showerrors then return error else return default end
	end
end

function p.getValue(frame)
	local param = frame.args[2]
	if param == "FETCH_WIKIDATA" then return p.claim(frame) else return param end
end

function p.pageId(frame)
	local entity = mw.wikibase.getEntityObject()
	if not entity then return nil else return entity.id end
end

function p.labelOf(frame)
	local id = frame.args[1]
	-- returns the label of the given entity/property id
	-- if no id is given, the one from the entity associated with the calling Wikipedia article is used
	if not id then
		local entity = mw.wikibase.getEntityObject()
		if not entity then return printError("entity-not-found") end
		id = entity.id
	end
	return mw.wikibase.label(id)
end

function p.sitelinkOf(frame)
	local id = frame.args[1]
	-- returns the Wikipedia article name of the given entity
	-- if no id is given, the one from the entity associated with the calling Wikipedia article is used
	if not id then
		local entity = mw.wikibase.getEntityObject()
		if not entity then return printError("entity-not-found") end
		id = entity.id
	end
	return mw.wikibase.sitelink(id)
end

function p.badges(frame)
	local site = frame.args[1]
	local id = frame.args[2]
	if not site then return printError("site-not-found") end
	local entity = mw.wikibase.getEntityObject(id)
	if not entity then return printError("entity-not-found") end
	local badges = entity.sitelinks[site].badges
	if badges then
		local result
		for idx = 1, #badges do
			if result then result = result .. "/" .. badges[idx] else result = badges[idx] end
		end
		return result
	end
end

-- call this in cases of script errors within a function instead of {{#invoke:Wikidata|<method>|...}} call {{#invoke:Wikidata|debug|<method>|...}}
function p.debug(frame)
	local func = frame.args[1]
	if func then
		-- create new parameter set, where the first parameter with the function name is removed
		local newargs = {}
		for key, val in pairs(frame.args) do
			if type(key) == "number" then
				if key > 1 then newargs[key - 1] = val end
			else
				newargs[key] = val
			end
		end
		frame.args = newargs
		local status, result = pcall(p[func], frame)
		if status then return result else return '<span class="error">' .. result .. '</span>' end
	else
		return '<span class="error">invalid parameters</span>'
	end
end

return p

Dit Module "Wikidata" is uit Wikipedia. De lijst van zijn auteurs is te zien in zijn historische.