Fischer, Stanley
McGraw-Hill, 1988
Buku Teks
by edited by David F. Heathfield
Macmillan, 1976
Buku Teks
McEachern, William A.
South-Western College Publishing, 2000
Buku Teks
McEachern, William A.
South-Western College Publishing, 1997
Buku Teks
Raykov, Tenko
Routledge, Taylor & Francis Group, 2008
Buku Teks