Martin, Carole, author
McGraw-Hill, 2012
Buku Teks
Fletcher, John, author
Duckworth, 1973
Buku Teks
Fry, Ron, author
Career Press, 2002
Buku Teks
Spradley, James P.
Halt, Rinehart and Winston, 1979
Buku Teks
Grosse, Eric F., author
[American Society for Training & Development Press, American Society for Training & Development Press], 2002
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