Goodrich, Leland M., author
Thomas Y. Crowell, 1961
Buku Teks
Coyle, David Cushman, 1887-1969, author
The New Americanan Library, 1962
Buku Teks
Whittaker, David J., author
Routledge, 1997
Buku Teks
by United Nations
UNESCO, 1951
Buku Teks
by United Nations
Departement of Public Information - United Nations, 1956
Buku Teks