Edwards, Robert
Rigby , 1970
Buku Teks
Wohlrabe, Raymond A.
J.B. Lippincott Co., 1956, 1956
Buku Teks
Howitt, William
Sydney University Press, 1972
Buku Teks
Edwards, Robert
Rigby, 1969
Buku Teks
Bechervaise, John Mayston
Rigby Limited , 1967
Buku Teks