O`Brien, James A., 1936-, author
McGraw-Hill/Irwin, 2004
Buku Teks
Oshry, Barry, author
Berrett-Koehler Publishers, Inc., 2007
Buku Teks
Casti, John L., author
Univesity of East London Library, 1994
Buku Teks
Albert Wirya S., author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2015
UI - Skripsi Membership
Lucas, Henry C., author
McGraw-Hill, 1985
Buku Teks