Hickman, Gill Robinson, author
Harcourt, 2001
Buku Teks
Miller, Lawrence M., author
John Wiley & Sons, 1978
Buku Teks
Prentice Hall Press, 1989
Buku Teks
Evan M. Berman [and others]
Sage, 2001
Buku Teks
Nankervis, Alan R., author
Thomas Nelson Australia, 1996
Buku Teks