Singleton, Paul, author
John Wiley & Sons, 1980
Buku Referensi
Hinsie, Leland E., author
Oxford University Press, 1960
Buku Referensi
Millington, T. Alaric, author
Barnes & Noble Books, 1971
Buku Referensi
Glenn, J. A., author
Harper and Row, 1984
Buku Referensi
Tver, David F.
Van Nostrand Reinhold Co., 1980
Buku Referensi