Cain, William E., author
Johns Hopkins University Press, 1984
Buku Teks
New York : William Marsh Rice University
Majalah, Jurnal, Buletin
edited by M.J. Toswell and E.M. Tyler
Routledge, 1996
Buku Referensi
Swets & Zeitlinger B.V., 1994
Majalah, Jurnal, Buletin
Turville-Petre, Thorlac, author
Blackwell Publishing, 2007
Buku Teks