Donaldson, Gordon
Double day, 1985
Buku Teks
Walker, Jarrett, author
Island Press, 2012
eBooks
Katcher, Bruce Leslie, author
American Management Association, 2007
eBooks
Kahn, Herman
Macmillan, 1972
Buku Teks
Foster, Provost, author
O'Reilly, 2013
Buku Teks