Wrensch, Dana L.
Kendall/Hunt, 1992
Buku Teks SO
Mader, Sylvia S.
McGraw-HIll, 1996
Buku Teks
by Robert J. Brooker ... [and others]
McGraw-Hill, 2008
Buku Teks
by Eldra Pearl Solomon [and others]
Saunders College , 1993
Buku Teks
Case, James F.
Macmillan, 1979
Buku Teks