Niko Amrulloh, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2015
UI - Tesis (Membership)
Brown, Robert H.
Witherby & co. Ltd., 1975
Buku Teks
Koh, Soon Kwang, Peter
Longmans, 1989
Buku Teks
Rodda, William H.
Prentice-Hall, 1955
Buku Teks
Brown, Robert H.
Witherby , 1975
Buku Teks