Thurman, Harold V.
Charles E. Merrill Publishing Company, 1975
Buku Teks
Williams, Joreme
Little, Brown And Company, 1962
Buku Teks
Davis, Richard A.
Wm.C. Brown Publishers, 1996
Buku Teks
edited by Richard C. Vetter
Voice of America, 1974
Buku Teks
Weyl, Peter K.
John Wiley & Sons, 1970
Buku Teks