Dolbeare, Kenneth M., author
D.C. Heath, 1985
Buku Teks
Kissler, Gary D., author
Addison-Wesley, 1991
Buku Referensi
Dyere, Everett D., author
McGraw-Hill, 1979
Buku Teks
Casper, Lynne M., author
Sage, 2000
Buku Teks
McConnell, Grant, author
Alfred A. Knopf, 1967
Buku Teks