United Nations Publications, 2004
Buku Teks
edited by James Barros
The Free Press, 1972
Buku Teks
Gross, Ernest A.
Harper & Brothers, 1962
Buku Teks
Sircar, Muhammad Jamiruddin, author
Form International, 2003
Buku Teks
Luard, Evan
St. Martin's Press, 1979
Buku Teks