Allen, Judy
Wiley, 2003
Buku Teks
edited by Brian Harvey, Henk van Luijk and Horst Steinmann
Prentice-Hall, 1994
Buku Teks
Brennan, Lynne
Platkus, 1991
Buku Teks
Langford, Beverly Y.
American Management Association, 2005
eBooks
Luki Indra Malik
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2019
UI - Tugas Akhir