Artikel Jurnal
Beckhard, Richard, author
Addison-Wesley, 1987
Buku Teks
Chirot, Daniel
Harcourt Brace Jovanivich, 1986
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Rose, Edward, 1946-, author
Prentice Hall/Financial Times, 2008
Buku Teks
Rose, Edward, 1946-, author
Prentice-Hall, 2001
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