Hussey, David E.
Pergamon Press, 1976
Buku Teks
Jones, Harry, 1911-
Gower Press , 1974
Buku Teks
edited by David W. Ewing
Harper & Brothers, 1958
Buku Teks
Steiner, George Albert, 1912-
Macmillan, 1969
Buku Teks
Le Breton, Preston P.
Prentice-Hall, 1961
Buku Teks