Routledge, 1996
Buku Teks
Mayer, Ann Elizabeth, author
Westview Press, 1995
Buku Teks
Carías, Allan-Randolph Brewer, author
Cambridge University Press, 2009
eBooks
Unesco, 1970
Buku Teks
co-edited by Jack L. Nelson and Vera M. Green
Human Rights Publishing Group, 1980
Buku Teks