Wright, Charles Robert
Random House, 1975
Buku Teks
Wright, Charles Robert
New York, N.Y. Random House 1966,
Buku Teks
Vivian, John
Kencana Prenada Media, 2008
Buku Teks
Grindstaff, Carl F.
Christopher Publishing House, 1981
Buku Teks
Foster, Lois E.
Prentice-Hall, 1981
Buku Teks