Cleland, David I.
McGraw-Hill, 1981
Buku Teks SO
[edited by] W. Grant Ireson, Clyde F. Coombs, Jr., Richard Y. Moss
McGraw-Hill, 1995
Buku Referensi
John E. Ullmann, editor, Donald A. Christman, Bert Holtje, associate editors.
John Wiley & Sons, 1986
Buku Referensi
Blanchard, Benjamin S.
Pearson/Prentice Hall, 2004
Buku Teks SO
Gilb, Tom
Addison-Wesley, 1988
Buku Teks SO