Bodard, Lucien
Atlantic Monthly Press Book, 1967
Buku Teks
Souter, Gerry
Andre Deutsch, 2015
Buku Referensi
Brown, T. Louise
New York Routledge 1991,
Buku Teks
Moyar, Mark
Cambridge University Press, 2006
Buku Teks
Knoebl, Kuno
Frederick A. Praeger , 1967
Buku Teks