Fulmer, Robert M., author
Richard D. Irwin , 1983
Buku Teks
Reis, Matthew, author
American Management Association, 2010
eBooks
Finlay, William W., author
McGraw-Hill, 1955
Buku Teks
Maier, Norman R.F., author
John Wiley & Sons, 1956
Buku Teks
Prentice-Hall, 1949
Buku Teks