Hughes, G. David, author
Addison-Wesley, 1978
Buku Teks
Lal, Rajiv, author
McGraw-Hill, 2005
Buku Teks
Bursk, Edward Collins, author
Prentice-Hall, 1975
Buku Teks
Quelch, John A., author
Prentice-Hall, 2001
Buku Teks
Bernhardt, Kenneth L
Bussiness Publications, 1985
Buku Teks