Robbins, Stephen P., author
Pearson Prentice Hall, 2005
Buku Teks
Cortada, James W., author
McGraw-Hill, 1994
Buku Referensi
UNESCO, 2004
Buku Teks
by J. David Spiceland ... [and others]
McGraw Hil , 2013
Buku Teks
Davis, Philip J., author
Springer, 2012
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