Moore, Kenneth D.
Random House , 1989
Buku Teks
Moore, Kenneth D, author
McGraw--Hill, 2007
Buku Teks
edited by Heather Fry, Steve Ketteridge and Stephanie Marshall
Routledge, 2009
Buku Referensi
Harwell, Joan M., author
Jossey-Bass, 2001
Buku Teks
Lemlech, Johanna Kasin
Harper & Row , 1979
Buku Teks