Brown, P. Charles
Oxford University Press, 1984
Buku Teks
Rexroad, Robert A.
John Wiley & Sons, 1983
Buku Teks
consultant editor, D.E. Hathway
Harrap, 1985
Buku Referensi
Dorian, A.F.
Elsevier Scientific Publishing Company, 1981
Buku Referensi
Trimble, Louis
Cambridge University Press, 1985
Buku Teks