Morton, Joyce
Prentice-Hall, 1998
Buku Teks
Hombs, Mary Ellen
ABC-Clio, 1990
Buku Teks
James, Vaughn E.
American Management Association, 2009
eBooks
De Vries, Mary Ann
Prentice-Hall, 1991
Buku Referensi
edited by Rachel Weber and Randall Crane
Oxford University Press, 2012
Buku Teks