Swerdlik, Mark E.
Mayfield Publishing Company, 1999
Buku Teks
Folks, J. Leroy
John Wiley & Sons, 1981
Buku Teks
Lamont, Douglas
Blackwell Publishers, 1996
Buku Referensi
Chang, David W.
Thomson/Delmar Learning, 2006
Buku Teks
Robbins, Robert R.
John Wiley & Sons, 1981
Buku Teks