Walker, Allan S.
Australian War Memorial, 1957
Buku Teks
Ronald E. Rice, Charles K. Atkin, editor
Sage Publications, Inc., 2001
Buku Teks
Roman, Murray
McGraw-Hill, 1983
Buku Teks
Brady, S.G.
Stackpole, 1963
Buku Teks
King, Chris
Longman, 1994
Buku Teks