Ayers, David
Blackwell Publishing, 2008
Buku Teks SO
Klarer, Mario, 1962-
Routledge, 2005
Buku Teks SO
Klarer, Mario, 1962-
Routledge, 2005
Buku Teks SO
Koelb, Clayton
Cornell University Press , 1988
Buku Teks SO
Crane, R.S.
University of Chicago Press, 1971
Buku Teks SO