- Snyder, John P., "Map Projections--A Working Manual", U.S. Geological Survey Professional Paper 1395 (Supersedes USGS Bulletin 1532), United State Government Printing Office, Washington D.C., 1987.
- Snyder, John P. and Voxland, Philip M., "An Album of Map Projections", U.S. Geological Survey Professional Paper 1453 , United State Government Printing Office, Washington D.C., 1989.
- "Cartographic Projection Procedures for the UNIX Environment- A User's Manual" by Gerald I. Evenden, USGS Open File Report 90-284and Release 4 Interim Reports (2003)
- Snyder, John P., "Flattening the Earth - Two Thousand Years of Map Projections", Univ. Chicago Press, 1993
- Wolfram Mathworld "Gnomonic Projection" http://mathworld.wolfram.com/GnomonicProjection.html Accessed: 12th November 2009
- "New Equal-Area Map Projections for Noncircular Regions", John P. Snyder, The American Cartographer, Vol 15, No. 4, October 1988, pp. 341-355.
- Snyder, John P., "Map Projections--A Working Manual", U.S. Geological Survey Professional Paper 1395 (Supersedes USGS Bulletin 1532), United State Government Printing Office, Washington D.C., 1987.
- "Software Documentation for GCTP General Cartographic Transformation Package", U.S. Geological Survey National Mapping Division, May 1982.
- Department of Land and Survey Technical Circular 1973/32 http://www.linz.govt.nz/docs/miscellaneous/nz-map-definition.pdf
- OSG Technical Report 4.1 http://www.linz.govt.nz/docs/miscellaneous/nzmg.pdf
- Formules et constantes pour le Calcul pour la projection cylindrique conforme à axe oblique et pour la transformation entre des systèmes de référence. http://www.swisstopo.admin.ch/internet/swisstopo/fr/home/topics/survey/sys/refsys/switzerland.parsysrelated1.31216.downloadList.77004.DownloadFile.tmp/swissprojectionfr.pdf