Willett, Allan H., author
University of Pennsylvania Press, 1951
Buku Teks
Hammond, J. D.
Foresman and Company, 1968
Buku Teks
by Herbert S. Denenberg ... [et al.]
Prentice-Hall, 1964
Buku Teks
Athern, James L., author
West , 1989
Buku Teks
Vaughan, Emmett J., author
John Wiley & Sons, 1996
Buku Teks