Brammer, Robert
Brooks/Cole Cengage Learning, 2012
Buku Teks SO
Choudhuri, Devika Dibya
Brooks/Cole Cengage Learning, 2012
Buku Teks SO
editor, Don C. Locke, Jane E. Myers, Edwin L. Herr
Sage, 2001
Buku Referensi
Thompson, Charles L.
Broooks/Cole, 1996
Buku Teks SO
Arbuckle, Dugald S.
Allyn and Bacon, 1961
Buku Teks SO