OConnor, Karen
Addison Wesley Longman, 2001
Buku Teks
Aranson, Peter H.
Winthrop, 1981
Buku Teks SO
Geer, John Gray
Wadsworth and Cengage Learning, 2012
Buku Teks SO
Corry, J. A.
University of Toronto Press, 1960
Buku Teks SO
Woll, Peter
Little, Brown, 1982
Buku Teks SO