Gup, Benton E., author
John Wiley & Sons, 1987
Buku Teks
Kolb, Burton A.
Irwin, 1988
Buku Teks
Van Horne, James C. (James Carter), 1935-, author
Prentice Hall International, 1995
Buku Teks
Johnson, Robert W., author
Allyn and Bacon, 1962
Buku Teks
Rees, Bill
Prentice-Hall, 1990
Buku Teks