Walker, Robert A.
The Dryden Press, 1953
Buku Teks
Patman, Wright, 1893-1976, author
Bantam Books, 1957
Buku Teks
edited by Nathan Glick
United Sates Information Agency, 1989
Buku Teks
United States Department of State, 1991
Buku Teks
Departemen Luar Negeri Amerika Serikat, 1991
Buku Teks