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Buku Teks
Austen, David, author
Taramedia, 2003
Buku Teks
Tim Peneliti HI P31 Setjen DPR-RI, 2002
Buku Teks
Richard Bagun, author
Universitas Indonesia, 1988
UI - Skripsi (Membership)
Kaligis, O.C. (Otto Cornelis), 1942-, author
O.C. Kaligis & Associates, 2003
Buku Teks