Holland, Audrey L., author
Plural Publishing, 2007
Buku Teks
Ivey, Allen E., author
Allyn and Bacon, 1996
Buku Teks
Gelfer, Marylou Pausewang, author
McGraw-Hill, 1996
Buku Teks
Arbuckle, Dugald S., author
Allyn and Bacon, 1961
Buku Teks
Hansen, James C., author
Allyn and Bacon , 1986
Buku Teks