French, Wendell L.
Harper & Row, 1985.
Buku Teks SO
Reis, Matthew
American Management Association, 2010
eBooks
This, Leslie E.
Addison-Wesley, 1974
Buku Teks
Dipboye, Robert L.
Harcourt Brace College, 1994
Buku Teks SO
Fulmer, Robert M.
Richard D. Irwin , 1983
Buku Teks