Graver, Robert T., author
Prentice-Hall, 2001
Buku Teks
Stultz, Russell Allen
Prentice-Hall, 1982
Buku Teks
Hult, Christine
Wadsworth, 1987
Buku Teks
Rowley, Jennifer
Kogan Page, 1991
Buku Teks
Cram, Carol M., author
Cengage Learning , 2012
Buku Teks