Patterson, James
John Wiley & Sons, 1993
Buku Teks
Dubin, Fred S.
McGraw-Hill, 1978
Buku Teks
Hardie, Glenn M.
Prentice-Hall, 1995
Buku Teks
Jurnal Teknologi, Vol. 21(4) Desember 2007 : 247-255, 2007
Artikel Jurnal
Krugen, Abe
Delmar Cengage Learning, 2013
Buku Teks SO