Snyder, John P. (1987). Map Projections: A Working Manual. U.S. Geological Survey Professional Paper. 1395. Washington, D.C.: United States Government Printing Office. Arhivirano iz originala na datum 2011-05-01. Pristupljeno 2014-03-17.
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Snyder, John P. (1987). Map Projections: A Working Manual. U.S. Geological Survey Professional Paper. 1395. Washington, D.C.: United States Government Printing Office. Arhivirano iz originala na datum 2011-05-01. Pristupljeno 2014-03-17.