William J. Hardcastle, John Laver, Fiona E. Gibbon, editor
Wiley-Blackweell, 2013
Buku Teks
Thampan, Palakasseril Kumaran
Oxford & IBH Publishing Co., 1981
Buku Referensi
Prentice-Hall, 1991
Buku Referensi
Frederick S. Merritt and Jonathan T. Ricketts, editor
McGraw-Hill, Inc, 1994
Buku Referensi
Falletta, Salvatore V., author
[American Society for Training & Development;, ], 2001
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