Bostwick, Burdette E., author
John Wiley & Sons, 1981
Buku Teks
Falcone, Paul, author
American Management Association, 2009
eBooks
Fry, Ron, author
Career Press, 2002
Buku Teks
Beveridge, Wilbert Esler, author
Allen & Unwin, 1975
Buku Teks
Maier, Norman R.F.
John Wiley & Sons, 1960
Buku Teks