Simpson, Sally S.
Cambridge University Press, 2002
Buku Teks
Buchanan, Cathy, author
The Center for Independent Studies, 1992
Buku Teks
Pepinsky, Harold E., editor
Oxford University Press, 1980
Buku Teks
Brusino, Justin, author
American Society for Training & Development, 2007
eBooks
Heckert, J. Brooks (Josiah Brooks), 1893-, author
Ronald Press, 1955
Buku Teks