Engel, Thomas
Pearson Prentice Hall, 2008
Buku Teks
Williams, Virginia R.
W.H. Freeman, 1967
Buku Teks SO
Woodbury, George
International Thomson, 1997
Buku Teks SO
Alberty, Robert A.541.3 ALB p
John Wiley & Sons, 1992
Buku Teks SO
Levine, Ira N.
McGraw-Hill, 1988
Buku Teks SO