References
- Brown , R. 1948 . Historical Geography of the United States , New York : Harcourt, Brace & World .
- James , P.E. 1942 . Latin America , New York : Odyssey Press .
- Strahler , A. 1951 . Physical Geography , New York : Wiley .
- Walker , W.J. 1993 . Schwendeman's Directory of College Geography of the United States , Richmond, KY : Geographical Studies and Research Center, Eastern Kentucky University .