Statistik Länderprofile

http://www.economywatch.com/economic-statistics/economic-indicators/Age_Structure/

http://www.indexmundi.com/belgium/demographics_profile.html

http://www.indexmundi.com/factbook/countries

http://cia-world-factbook.realclearworld.com/l/289/Belgium

http://perspective.usherbrooke.ca/bilan/servlet/BMPagePyramide?codePays=ESP