edited by Donald Peter Cushman and Sarah Sanderson King
University of New York Press, 1995
Buku Teks SO
Quirke, Bill
McGraw-Hill, 1996
Buku Teks SO
Artikel Jurnal
Berko, Roy M
Houghton Miffiln, 2001
Buku Teks
Palmer, Ian R.
McGraw-Hill, 2006
Buku Teks