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Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2008

 UI - Skripsi (Open)

Velasquez, Manuel G., author

Pearson, 2006

 Buku Teks

Weiss, Joseph, author

Wadsworth, 2009

 Buku Teks

Pearson Education , 2005 2005

 Multimedia

Hodges, Luther H., author

Prentice-Hall, 1963

 Buku Teks