Fry, T. F., author
Butterworth, 1981
Buku Teks
Sandige, Richard S., author
McGraw-Hill, 2012
Buku Teks
Brookshear, J. Glenn, author
Pearson, 2015
Buku Teks
Spencer, Donald D., author
Prentice-Hall, 1974
Buku Referensi
Freedman, Alan, author
Amacom, 1995
Buku Referensi