Smith, L. Glenn
Allyn and Bacon, 1973
Buku Teks
John Sikula, senior editor ; Thomas Buttery, editor, Edith Guyton, editor
Macmillan Library Reference USA, 1996
Buku Referensi
Pitoyo
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2011
UI - Tesis Open
Wang, Jianpan
Gale Asia Cengage Learning, 2013
Multimedia
Wang Jianpan, editor
Gale Asia, Cengage Learning, 2012
Buku Teks SO