Walthall, Wylie A., author
Harper and Row, 1987
Buku Teks
Pride, William M., author
South Western Cengage Learning, 2012
Buku Teks
Madura, Jeff, author
South-Western College, 2001
Buku Teks
Straub, Joseph T., author
Kent, 1985
Buku Teks
Cunningham, William H., author
South-Western, 1984
Buku Teks