Highsmith, Richard M., Jr.
J.B.Lippincott Co., 1963
Buku Teks
Hudson, Ray, author
Prentice-Hall, 2000
Buku Teks
Pounds, Norman J. G., author
Silver Burdett, 1980
Buku Teks
Thatcher, W.S., author
English University Press, 1957
Buku Teks
Wheeler, James O., author
John Wiley & Sons, 1986
Buku Teks