ITRF on International Earth Rotation Service home page: http://www.iers.org/iers/products/itrf/ 

Economic Commission for Africa – CODI  http://www.uneca.org/eca_resources/documents_DISD.htm 

Organisation for African Unity July 2001document: http://www.dfa.gov.za/events/afrinit.htm 

International Association of Geodesy home page: http://www.gfy.ku.dk/~iag/ 

International GPS Service home page: http://igscb.jpl.nasa.gov/ 

International Federation of Surveys : http://www.fig.net/ 

EUREF home page: http://www.igeo.pt/euref/ 

SIRGAS Report to IAG: http://www.gfy.ku.dk/~iag/Travaux_99/sirgas.htm 

Trimble Donates GPS Reference Stations to Africa: http://www.uneca.org/disd/news/istd-dna-2007111301-en.asp