Musser, Gary L., author
John Wiley & Sons, 2004
Buku Teks
Moursund, David G., author
John Wiley & Sons, 1981
Buku Teks
Nichols, Eugene D.
Holt, Rinehart and Winston, 1971
Buku Teks
Bitter, Gary G., author
Allyn and Bacon, 1989
Buku Teks
May, Lola June
The Free Press, 1970
Buku Teks