Roger E. Schechter, editor
WEST, 2011
Buku Teks
West Publishing, 1995
Buku Teks
Ward, Francine, author
American Society for Training & Development, 2007
eBooks
McManis, Charles R., author
West Publishing, 1992
Buku Teks
Weston, Glen E.
West Publishing CO, 1992
Buku Teks