Fisher, Roger
Oxford University Press, 1978
Buku Teks
edited by Daniel Frei
Sage, 1982
Buku Teks
Zouhair Al Hassani
Cambridge University Press , 2008
Artikel Jurnal
Shaw, Malcolm Nathan, 1947-
Cambridge University Press, 2017
Buku Teks
Fenwick, Charles G.
Appleton-Century-Crofts, 1948
Buku Teks