Gross, Ernest A.
Harper & Brothers, 1962
Buku Teks
Goodrich, Leland M., author
Thomas Y. Crowell, 1961
Buku Teks
Coyle, David Cushman, 1887-1969, author
Columbia University Press, 1963
Buku Teks
United Nations Department of Public Information, 1989
Buku Teks
Department of Republic Information United Nations, 1992
Buku Teks