"Countries Compared by Economy > Budget > Revenues. International Statistics at NationMaster.com", CIA World Factbooks 18 December 2003 to 28 March 2011. Aggregates compiled by NationMaster. Retrieved from http://www.nationmaster.com/country-info/group-stats/Western-Europe/Economy/Budget/Revenues
"Countries Compared by Economy > Budget > Revenues. International Statistics at NationMaster.com, CIA World Factbooks 18 December 2003 to 28 March 2011. Aggregates compiled by NationMaster." 1997-2013. <http://www.nationmaster.com/country-info/group-stats/Western-Europe/Economy/Budget/Revenues>.
'Countries Compared by Economy > Budget > Revenues. International Statistics at NationMaster.com, CIA World Factbooks 18 December 2003 to 28 March 2011. Aggregates compiled by NationMaster.', <http://www.nationmaster.com/country-info/group-stats/Western-Europe/Economy/Budget/Revenues> [assessed 1997-2013]
"Countries Compared by Economy > Budget > Revenues. International Statistics at NationMaster.com", CIA World Factbooks 18 December 2003 to 28 March 2011. Aggregates compiled by NationMaster. [Internet]. 1997-2013. Avaliable from: <http://www.nationmaster.com/country-info/group-stats/Western-Europe/Economy/Budget/Revenues>.
"Countries Compared by Economy > Budget > Revenues. International Statistics at NationMaster.com", CIA World Factbooks 18 December 2003 to 28 March 2011. Aggregates compiled by NationMaster. Avaliable at: nationmaster.com. Assessed 1997-2013.
"Countries Compared by Economy > Budget > Revenues. International Statistics at NationMaster.com, CIA World Factbooks 18 December 2003 to 28 March 2011. Aggregates compiled by NationMaster.," http://www.nationmaster.com/country-info/group-stats/Western-Europe/Economy/Budget/Revenues (assessed 1997-2013)
"Countries Compared by Economy > Budget > Revenues. International Statistics at NationMaster.com", CIA World Factbooks 18 December 2003 to 28 March 2011. Aggregates compiled by NationMaster., http://www.nationmaster.com/country-info/group-stats/Western-Europe/Economy/Budget/Revenues (last visited 1997-2013)
"Countries Compared by Economy > Budget > Revenues. International Statistics at NationMaster.com", CIA World Factbooks 18 December 2003 to 28 March 2011. Aggregates compiled by NationMaster., http://www.nationmaster.com/country-info/group-stats/Western-Europe/Economy/Budget/Revenues (as of 1997-2013)