De Blij, Harm J.
John Wiley & Sons, 19880
Buku Teks
Knapp, B.J.
George Allen and Unwin, 1982
Buku Teks
Hidore, John J.
Scott, Foresman, 1974
Buku Teks
VanCleave, Janice Pratt
Pustaka Utama Grafiti, 1993
Buku Teks
Heintzelman, Oliver H.
Prentice-Hall, 1960
Buku Teks