Napitupulu, Harmoni
Program Pascasarjana Universitas Indonesia, 2013
UI - Tesis (Membership)
Osborne, Larry N.
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Buku Teks
Sivazlian, B.D.
Prentice-Hall, 1975
Buku Teks
Hare, Van Court
Harcourt, Brace and World, 1967
Buku Teks
Hawryszkiewycz, Igor Titus
Prentice-Hall, 1988
Buku Teks