Temes, Roberta
American Management Association, 2009
eBooks
Sitompul, A. R Adelany
2001
UI - Skripsi Membership
Routledge, 1997
Buku Teks
William J. Buckley, Karen S. Feldt, editor and introduction
McGraw-Hill, 2013
Buku Teks
[publisher not identified], [date of publication not identified]
Naskah