Southworth, George C.
Gordon and Breac, 1962
Buku Teks
Blain, Ellis, author
Methuen Of Australia, 1977
Buku Teks
Fitzgerald, Robert D.
Angus and Roberson Publishers, 1965
Buku Teks
Reinhardt, George C.
Dobleday, 1960
Buku Teks
Pimentel, George C., author
Holden-Day, 1971
Buku Teks