Mazur, Laura
John Wiley & Sons, 2009
Buku Teks
edited by Donald Snow ; foreword by Patrick F. Noonan
Island Press, 1992
Buku Teks
Artikel Jurnal
editor, Hans J. Keller
VisionLink Education Foundation, 1993
Buku Referensi
Situmorang, Lisken L.M.
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2010
UI - Tesis Open