Lewis, Norman, author
Harper & Row , 1962
Buku Referensi
Oxford University press , 1994
Buku Teks
Wilkes, G. A. (Gerald Alfred), 1927-, author
Fortana/Collins, 1980
Buku Referensi
Jones, David J., author
Australia, Second Back Row Press
Buku Referensi
Jones, David J.
Second Back Row Press, 1981
Buku Teks