American Psychological Association, 2002
Buku Teks
Casteleyn, Mary, author
Aslib, 1996
Buku Teks
Gusti Ardiansyah, author
Universitas Indonesia, 2009
UI - Tesis (Open)
Agus Rohmani, author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2010
UI - Tesis (Open)
United States. Department of Labor
Illinois : The United States Departemen of Labor, 1994, 1995
Buku Referensi