Bregman, Allyn A., author
John Wiley & Sons, 1983
Buku Teks
Bregman, Allyn, author
John Wiley & Sons, 1990
Buku Teks
Norstog, Knut, author
Northern Illinois University, 1969
Buku Teks
Choinski, John S.
Wm.C. Brown Pub., 1992
Buku Teks
Gardner, Eldon J., author
Burgess, 1975
Buku Teks