Goodrich, Leland M.
Thomas Y. Crowell, 1961
Buku Teks
Wright, Quincy
Asia Publishing House, 1960
Buku Teks
United Nations, [date of publication not identified]
Buku Teks
United Nations, 1966
Buku Teks
Departemen of Public Information UN, 1989
Buku Teks