Oxford University Press, 1951
Buku Teks
Huzzar, George B, De
Thomas Y.Crowell Company, 1955
Buku Teks
Jimenez, Emmanuel
The johns Hopkins University Press, 1987
Buku Teks
Zvorykin, A.A., author
UNESCO, 1977
Buku Teks
Beloff, Max, author
Oxford University Press, 1947
Buku Teks