Langefors, Borje, author
Petrocelli, 1976
Buku Teks
Rowley, J.E., author
Ashgate, 1992
Buku Teks
Artikel Jurnal
by Ilene F. Rockman ... [and others]
Jossey-Bass, 2004
Buku Teks
Rizky Eriko, author
Fakultas Ilmu Komputer Universitas Indonesia, 2013
UI - Tugas Akhir