Mahmoud, Shah, author
Betterway, 1992
Buku Referensi
Traister, John E., author
Prentice-Hall, 1986
Buku Teks
Herbert, Anthony B.
Macmillan Publishing Co., 1983
Buku Teks
Juran, J. M. (Joseph M.), 1904-2008, author
McGraw-Hill, 2010
Buku Teks
Knackstedt, Mary V., author
Wiley, 2005
Buku Referensi