Harris, D.D. (Donald Dunstan)
Whitcombe Tombs PTY, 1963
Buku Teks
Tweedie, Alan D., author
Longmans, 1965
Buku Teks
The Association, 1957
Buku Teks
Wohlrabe, Raymond A.
J.B. Lippincott Co., 1956, 1956
Buku Teks
Berney, Maurice
Angus and Robertson, 1965
Buku Teks