Skinner, Brian J., author
John Wiley & Sons, 1987
Buku Teks
Fried, Vojtech, author
McGraw-Hill, 1977
Buku Teks
Trewartha, Glenn T., author
McGraw-Hill, 1967
Buku Teks
Poirier, Frank E., author
Burgess Publishing, 1974
Buku Teks
Nelson, Harry, author
West Publishing, 1988
Buku Teks