Nesa, Wu, author
McGraw-Hill, 1981
Buku Teks
Hadley, G., author
Addison-Wesley, 1962
Buku Teks
Gass, Saul I., author
Mc Graw Hill, 1975
Buku Teks
Ignizio, James P., author
Sage, 1985
Buku Teks
Feiring, Bruce R., author
Sage University Paper, 1986
Buku Teks