Ellsworth, John W
McGraw-Hill, 1976
Buku Teks
Idris Thaha, author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2004
UI - Tesis (Membership)
Dyke, Vernon van, author
Nelson, 1992
Buku Teks
Academy of Political Science, 2018
Majalah, Jurnal, Buletin
Jacobsen, Gertude Ann
Barnes & Noble, 1951
Buku Teks