Wharley, W. Gordon
Harper & Row, 1964
Buku Teks
edited by Peter J. Lea, Richard C. Leegood
John Wiley & Sons, 1993
Buku Teks
Bailey, Paul C.
International Textbook Company, 1969
Buku Teks
Jones, Kenneth G.
John Wiley & Sons, 1977
Buku Teks
Mader, Sylvia S.
McGraw-HIll, 1996
Buku Teks