Roberts, Richard A., 1935-, author
Massachusetts Addison-Wesley, 1992
Buku Teks
Burger, H. Robert, author
W.W. Norton & Company, 2006
Buku Teks
Stewart, Kenneth G., author
Thomson Broocks, 2005
Buku Teks
Muchinsky, Paul M., author
Wadsworth, 2000
Buku Teks
Moon, Francis C., author
John Wiley & Sons, 1992
Buku Teks