Ohta, Amy Snyder, author
Lawrence Erlbaum Associates Publ, 2001
Buku Teks
Corbett, Wendy Gates, author
American Management Association, 2009
eBooks
Plack, Margaret M., author
Slack Incorporated, 2011
Buku Teks
Cracolice, Mark S., author
Thomson, Brooks/Cole, 2007
Buku Teks
Clarke, D.A., author
DP Pub., 1994
Buku Teks