Bonset, Helge
Coutinho, 1992
Buku Teks
Thornton, Geoffrey
Edward Arnold, 1980
Buku Teks
Isbell, Rebecca T., author
Wadsworth and Cengage Learning, 2013
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Gelineau, R. Phyllis, author
Cengage Learning , 2012
Buku Teks
Downs, Lisa J., author
American Society for Training & Development, 2008
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