Pounds, Norman J. G., author
McGraw-Hill, 1972
Buku Teks
Goblet, Y.M.
Prederick A. Praeger, 1955
Buku Teks
East, W. Gordon
Macmillan, 1975
Buku Teks
Short, John Rennie, author
Routledge, 1994
Buku Teks
edited by, Alan D. Burnett and Peter J. Taylor
John Wiley & Sons, 1981
Buku Teks