Muhammad Iqbal, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2013
UI - Skripsi (Membership)
Bethel, Lawrence L., author
McGraw-Hill Kogakusha, 1971
Buku Teks
Davis, Ralph Currier, author
Harper & Row, 1940
Buku Teks
Blake, Robert R.
Gulf Pub. Co., Book Division, 1978
Buku Teks
Heydebrand, Wolf V.
Prentice Hall Inc., 1973
Buku Teks