Goodrich, Leland M.
Thomas Y. Crowell, 1961
Buku Teks
United Nations Publications, 1975
Buku Teks
Departemen of Public Information UN, 1989
Buku Teks
Departemen of Public Information UN, 2014
Buku Teks
Coyle, David Cushman, 1887-1969
Columbia University Press, 1963
Buku Teks