Hamilton, Robert W.
St. Paul, Minn, 1989
Buku Teks
Engler, George N.
Business Publications , 1982
Buku Teks
Hamilton, Robert W.
West Publishing, 1984
Buku Teks
Axelrod, Alan
Little, Brown, 1970
Buku Teks
Hunt, Pearson
Richard D. Irwin, [Date of publication not identified]
Buku Teks