edited by Peter Burke
Pennsylvania State University Press, 1995
Buku Teks SO
Fedrizzi, Mariann
South Western Cengage Learning, 2011
Buku Teks SO
edited by Raymond E. Dumett
Longman, 1999
Buku Teks SO
MIT Press, 1977
Buku Teks SO
edited by Lesley Brown
Clarendon Press, 1993
Buku Referensi