Findley, Roger W.
West Publishing, 1992
Buku Teks
Findley, Roger W.
West Publishing, 1996
Buku Teks
Guruswamy, Lakshman D.
Thomson/West, 2012
Buku Teks
Kubasek, Nancy K.
Pearson - Prentice Hall, 2005
Buku Teks
Doelle, Meinhard
Carswell, 2009
Buku Teks