Maguire, Keith
Chambers, 1991
Buku Teks SO
Friska Sari Ronadiba
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2008
UI - Tesis Open
edited Iman G. Lanti, Greg Mils, Sigit Wardono
Pustaka Cidesindo, 1997
Buku Teks SO
Sachs, Albie
University of California Press, 1973
Buku Teks SO
Gandhi, M.K., 1869-1948
Ahmedabad Navajivan Publishing House 1928
Buku Teks