Rijanto Tosin, author
Dinastindo, 1991
Buku Referensi
Ryan, Daniel, author
Brooks / Cole Pub, 1983
Buku Teks
Skees, William D.
Lifetime Learning Publications, 1982
Buku Teks
Freedman, Alan, author
Amacom, 1995
Buku Referensi
Coughlin, Robert F., author
Prentice-Hall, 1968
Buku Referensi