Radjali Mukhlis
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2004
UI - Skripsi Membership
Gorki, Maxim
T. Werner Laurie, [Date of publication not identified]
Buku Teks SO
Gedes & Grosset, 2001
Buku Referensi
Foy, Nancy
Eyre Methuen, 1974
Buku Teks SO
by Stewart Sutherland ... [and others]
Routledge, 1988
Buku Teks SO