Eggert, Jim, author
William Kaufmann, 1979
Buku Teks
Freeman, A. Myrick, 1936-, author
Harper & Row , 1983
Buku Teks
Hartley, Keith
John Wiley & Sons, c.1981
Buku Teks
Jehle, Geoffrey A., author
Prentice-Hall, 1991
Buku Teks
Katz, Michael L., author
Irwin McGraw-Hill, 1998
Buku Teks