Nourse, Alan E.
Time Incorporated, 1964
Buku Referensi
Ambrose, Timothy
Routledge, 1995
Buku Teks SO
Donatelle, Rebecca J.
Allyn and Bacon , 1997
Buku Teks SO
Macionis, John J.
Prentice-Hall, 2000
Buku Teks
Willmore, Joe
[American Society for Training and Development Press;, ], 2004
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