Simanjuntak, Sangap Prawira
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2004
UI - Tesis Membership
Allen, Peter
Pitman, 1998
Buku Teks SO
Rodgers, Mark
McGraw-Hill , 2011
Buku Teks SO
Wingate, John W.
South-Western Publishing, 1959
Buku Teks SO
Kurtz, David L.
Business Publications, 1982
Buku Teks SO