Rae, Leslie
McGraw-Hill, 1994
Buku Referensi
Mackenizie, John
Illinois: Dow Jones-Irwin, 1989
Buku Teks
Becker, Esther R., author
Harper & Row, 1971
Buku Referensi
Lambert, Brian, author
American Society for Training & Development, 2010
eBooks
Richardson, Linda, author
McGraw-Hill, 2003
Buku Teks