Ellis, Roger B., author
Churchill Livingstone, 2004
Buku Teks
by Paul A. Fritz ... [and others]
Appleton-Century-Crofts, 1984
Buku Teks
Hein, Eleanor C., author
Little, Brown, 1980
Buku Teks
Hartley, Peter, 1946-, author
Roudledge, 1993
Buku Teks
Condon, John C., author
Macmillan, 1977
Buku Teks