Ayers, David
Blackwell Publishing, 2008
Buku Teks
Klarer, Mario, 1962-
Routledge, 2005
Buku Teks
Klarer, Mario, 1962-
Routledge, 2005
Buku Teks
Koelb, Clayton
Cornell University Press , 1988
Buku Teks
edited by Ralph Cohen
Sheridan Press, 1989
Buku Referensi