New-York: Prentice Hall, 1993,
Buku Referensi
Heisler, Sanford I, author
John Wiley & Sons, 1984
Buku Referensi
edited by Andrew Heritage
Dorling Kindersley, 2000
Buku Referensi
Sriro, Andrew I., author
Equinox Publishing, 2006
Buku Teks
Sriro, Andrew I., author
Equinox Pub., , 2005
Buku Referensi