Brady, George S.
McGraw-Hill, 1979
Buku Referensi
Schweitzer, Glenn E., author
American Chemical Society, 1984
Buku Teks
Hicks, Lawrence E., author
Mamerican Management Association , 1972
Buku Teks
Hildreth, Ronald B.
Practising Law Institute, 1993
Buku Teks
N.Y. AMA , 1982
Buku Teks