Angell, David
Addison-Wesley Publishing Company, Inc., 1994
Buku Teks
Harris, Robert A., author
Pyrczak Pub, 2011
Buku Teks
Markus, John, 1911-, author
McGraw-Hill, 1971
Buku Referensi
De Vries, Mary Ann, author
Macmillan, 1994
Buku Teks
Levinson, Nan, author
[American Management Association;, ], 2000
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