Bregman, Allyn
John Wiley & Sons, 1990
Buku Teks SO
Norstog, Knut
Northern Illinois University, 1969
Buku Teks SO
Choinski, John S.
Wm.C. Brown Pub., 1992
Buku Teks SO
Gardner, Eldon J.
Burgess, 1975
Buku Teks SO
Vodopich, Darrell S.
McGraw-Hill, 2008
Buku Teks SO