Johnson, Luke, author
Penguin book, 2013
Buku Teks
Brandt, Steven C., author
Pustaka Binaman Pressindo, 1985
Buku Teks
Aulet, Bill, 1958-, author
John Wiley & Sons, 2013
Buku Teks
Schlivek, Louis B., author
Doubleday, 1965
Buku Teks
Finell, Dorothy, author
American Management Association, 2007
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