Ellis, Janice Rider, author
J.B. Lippincott, 2007
Buku Teks
Lesikar, Raymond V. (Raymond Vincent), author
McGraw-Hill/Irwin , 2002
Buku Teks
Stephen, Revare.
Nexus, 2010
Buku Teks
Revere, Stephen
Traveler's Korean, 2007
Buku Teks
Atwood, Christee Gabour, author
American Society for Training & Development, 2009
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