Ndubuisi Ekekwe
IGI Global, 2012
Buku Teks
Gerhard Busse, editor
Taylor and Francis, 2008
Buku Teks
Christensen, Clayton M., author
Harvard Business School Press, 2004
Buku Teks
Bright, James R., author
R. D. Irwin , 1964
Buku Teks
Nathan, author
Fakultas Ilmu Komputer Universitas Indonesia, 2013
UI - Skripsi (Membership)