Clark, Mary Jo
Appleton & Lange, 1999
Buku Teks
Lamb, Charles W.
Houghton Mifflin, 1987
Buku Teks
Folks, J. Leroy
John Wiley & Sons, 1981
Buku Teks
Lamont, Douglas
Blackwell Publishers, 1996
Buku Referensi
Meriam, J.L. (James L.)
John Wiley & Sons, 1976
Buku Referensi