Gilluly, James, author
W.H. Freeman, 1959
Buku Teks
by Robert Horton [and others]
Prentice-Hall, 1996
Buku Teks
Voet, Donald J., author
John Wiley & Sons, 2008
Buku Teks
Mankiw, N. Gregory, author
Harcout College, 1998
Buku Teks
Sutherland, Edwin H., author
Lippincott Company, 1960
Buku Teks