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
Webdy R.Uhlmann, Jane L. Schuette, Baverly M. Yashar, Beverly M., editor
John Wiley & Sons, 2009
Buku Teks