1. 1S Brooker, NMR Beasley, and M Ndinaromtanet al. (2002 ) Application of Remote Sensing and Geographical Information Systems: The Design of a Sampling Strategy for a National Helminth Survey in Chad . Bulletin of the World Health Organization (in press).
2. 3AA Buck, RI Anderson, TT Sasaki, and K Kawata (1970 )Health and Disease in Chad: Epidemiology, Culture and Environment in Five Villages. Johns Hopkins Press, Baltimore.
3. 4U Deichmann (1996 )African Population Database Documentation. UNEP/GRID (http://grid2.cr.usgs.gov/globalpop/index/html).