Brammer, Robert, author
Thomson, 2004
Buku Teks
Brammer, Robert, author
Brooks/Cole Cengage Learning, 2012
Buku Teks
Choudhuri, Devika Dibya, author
Brooks/Cole Cengage Learning, 2012
Buku Teks
editor, Don C. Locke, Jane E. Myers, Edwin L. Herr
Sage, 2001
Buku Referensi
Arbuckle, Dugald S., author
Allyn and Bacon, 1961
Buku Teks