Afqi Maulana, author
Putra Pelajar, 2000
Buku Teks
Kinlaw, Dennis C.
Lexington Books, 1991
Buku Teks
Kymlicka, Will, author
OxfordClarendon Press, 1995
Buku Teks
Amoo, Sam G.
United Nations Development Programme, 1997
Buku Teks
Luft, Joseph, author
Mayfield Publishing Company, 1984
Buku Teks