Kroenke, David M., 1946-, author
Mitchell Publishing, 1987
Buku Teks
O`Brien, James A., 1936-, author
Richard D. Irwin, 1975
Buku Teks
Fuori, William M., author
Prentice-Hall, 1981
Buku Teks
Madura, Jeff, author
South-Western College, 2001
Buku Teks
Cunningham, William H., author
South-Western, 1984
Buku Teks