Atwan, Robert, author
McGraw-Hill, 1987
Buku Teks
Cambridge University Press, 1990
Buku Teks
Madsen, David, 1929-, author
Jossey-Bass, 1992
Buku Teks
Campbell, William Giles, author
Hoghton Mifflin, 1990
Buku Teks
Hillway, Tyrus, author
Houghton Miffiln, 1964
Buku Teks