Finnie, David H.
Harvard University Press, 1958
Buku Teks
Harari, Maurice, author
Prentice-Hall, 1962
Buku Teks
edited by Sydney Nettleton Fisher
Cornell University Press , 1955
Buku Teks
edited by Hussein Hassan Soliman
Routledge, 2013
Buku Teks
Held, Colbert C., author
Westview Press, 1989
Buku Teks