edited by Michael Bonell, Maynard M. Hufschmidt, John S. Gladwell
Cambridge University Press , 1993
Buku Teks
Larry W. Mays, editor in chief
McGraw-Hill, 1996
Buku Referensi
McDonald, Adrian T., author
Wiley, 1988
Buku Teks
Artikel Jurnal
James, L. Douglas (Leonard Douglas), author
McGraw-Hill, 1971
Buku Teks