Plucknett, Theodore F. T.
Little, Brown and Company, 1956
Buku Teks
Fawcett, J.E.S.
Penguin Books, 1971
Buku Teks
Younger, R. M.
Victoria Hutchinson Group 1982
Buku Teks
Goldschmidt, Arthur
Westview Press, 1983
Buku Teks
editor Thomas C. Cochran, Wayne Andrew
Charles Scribner's Sons , 1962
Buku Referensi