Proehl, Rebecca Ann, author
Sage, 2001
Buku Teks
Senior, Barbar, author
Prentice-Hall, 2006
Buku Teks
Jones, Gareth R., author
Pearson, 2010
Buku Teks
Dunphy, Dexter C., author
McGraw-Hill, 1985
Buku Teks
Michael, Stephen R., author
McGraw-Hill, 1981
Buku Teks