Kay, Dennis, author
Twayne, 1995
Buku Teks
Campbell, David, author
University of Queensland Press, 1975
Buku Teks
Beaver, Bruce, author
University of Queensland Press, 1972
Buku Teks
edited by Geoffrey Barraclough
Times Books, 1984
Buku Referensi
Published for Newsweek by Funk & Wagnalls, 1950
Buku Teks