Sellers, Charles
Rand Mcnally Publishing, 1974
Buku Teks
edited by Frank Freidel and Norman Pollack
Rand McNally, 1963
Buku Teks
Adams, James Truslow, author
1946
Buku Referensi
editor Thomas C. Cochran, Wayne Andrew
Charles Scribner's Sons , 1962
Buku Referensi
U.S. Information Service,, 1981
Buku Teks