Rosenberg, Jerry M., author
John Wiley & Sons, 1993
Buku Referensi
edited by Sybil P. Parker
New York, McGraw-Hill
Buku Referensi
Watson, Hugh J., author
Businesss Publications , 1980
Buku Teks
Sanders, Donald H., author
McGraw-Hill, 1979
Buku Teks
O`Brien, James A., 1936-, author
Richard D. Irwin, 1975
Buku Teks