Shubin, John A.
Barnes & Noble, 1975
Buku Teks SO
Walthall, Wylie A.
Harper and Row, 1987
Buku Teks
Griffin, Ricky W.
Prentice-Hall, 2002
Buku Teks
Bovee, Courtland L.
Pearson/Prentice-Hall, 2007
Buku Teks
Boone, Louis E.
Dryden Press, 1996
Buku Teks