edited by M.J. Toswell and E.M. Tyler
Routledge, 1996
Buku Referensi
Tarner, Margaret
Dian Rakyat, 1991
Buku Teks SO
Archipelago Press , 1998
Buku Teks SO
Moore, Colette
Cambridge University Press , 2011
Buku Teks SO
Coleman, John R.
Cambridge University Press, 2005
Buku Teks SO