Moverley, John, author
Harper-Collins, 1986
Buku Teks
Tower, Ralph B., author
Prentice-Hall, 1991
Buku Teks
Klooster, Dale H., author
South-Western Publishing, 1983
Buku Teks
Klooster, Dale H., author
South-Western, 1990
Buku Teks
Oxford University Press , 1985
Buku Teks