Crawford, John W., author
Allyn and Bacon, 1965
Buku Teks
White, Roderick, author
McGraw-Hill, 2000
Buku Teks
White, Roderick, author
McGraww-Hill , 2000
Buku Teks
by John S. Wright ... [et.al.]
McGraw-Hill, 1977
Buku Teks
Aaker, David A., author
Prentice-Hall, 1987
Buku Teks