Clarke, Arthur C.
Harper and Row, 1965
Buku Teks
Feiling, Keith
Macmillan, 1951
Buku Teks
Gronbach, Kenneth W.
American Management Association, 2008
eBooks
Atkinson, William Illsey
American Management Association, 2003
eBooks
Atkinson, William Illsey
Amacom, 2003
Buku Teks