Lawrence M. Salinger, editor
Sage Reference, 2013
Buku Referensi
Mills, C. Wright, author
Oxford University Press, 1951
Buku Teks
Brickey, Kathleen F., author
Litt;e, Brown, 1995
Buku Teks
edited by Cary L. Cooper and Judi Marshall
John Wiley & Sons, 1980
Buku Teks
Magnuson, Roger J., author
McGraw-Hill, 1992
Buku Teks