McEachern, William A.
South-Western College Publishing, 1997
Buku Teks SO
McEachern, William A.
South-Western College Publishing, 2000
Buku Teks SO
McEachern, William A.
South-Western College Publishing, 2000
Buku Teks SO
Parkin, Michael, 1939-
Prentice-Hall, c1992
Buku Referensi
Morley, Samuel A.
The Dryden Press, 1984
Buku Teks