Gillis, Angela
F.A. Davis , 2002
Buku Teks
Campbell, Enid Mona, author
[publisher not identified], [date of publication not identified]
Buku Teks
Johnson, Janet Buttolph, 1950-, author
CQ Press, 2012
Buku Teks
Checkoway, Harvey
Oxford University Press , 1989
Buku Teks
Zikmund, William G., author
South-Western Cengage Learning, 2013
Buku Teks