Rucker, Bryce W., author
The Iowa State Univ. Press, 1964
Buku Teks
Mega Apridita, author
Universitas Indonesia Fakultas Ekonomi Bisnis, 2016
UI - Skripsi (Membership)
Izard, Halph S., author
Hunt Publishing Company, 1977
Buku Teks
Mac Dangall, Curtis D., author
Macmillan, 1967
Buku Teks
Yusuf Hadli, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2014
UI - Skripsi (Membership)