Pettinger, Richard
Capstone Publishing, 2002
Buku Teks
Greenberg, Jerald, author
Buku Teks
Benjamin Schneider
lawrence Erlbaum Associates , 2004
Buku Teks
Heneman III, Herbert G., author
McGraw-Hill, 2009
Buku Teks
edited by Benjamin Schneider
Lawrence erlbaum associates, 2004
Buku Teks