Ellis, Harry B., author
World Pub., 1965
Buku Teks
Swann, Dennis, author
Penguin Books , 1972
Buku Teks
Krause, Lawrence B., author
Prentice-Hall, 1964
Buku Teks
Savage, Khatarine, author
Walck, 1969
Buku Teks
Holt, Stephen, author
Hamish Hamilton, 1967
Buku Teks