Kamen, Henry, author
Routledge, 2000
Buku Referensi
White, James L., author
Washington Square Press, 1966
Buku Teks
edited by Norman F. Cantor and Samuel Berner
Thomas Y. Crowell, 1970
Buku Teks
Jackson, J. Hampden, author
Cambridge University Press, 1941
Buku Teks
Garrett, Mitchell B.
Appleton-Century-Crofts, , 1947
Buku Teks