Julie R O'Sullivan
West, 2012
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
Podgor, Ellen S., author
West Publishing, 1993
Buku Teks
Mills, C. Wright, author
Oxford University Press, 1951
Buku Teks