IBM Corporation , 2000
Buku Teks
Bernard, Josef, author
Dow Jones-Irwin, 1986
Buku Referensi
Astrid Vega Septyanti, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2017
UI - Skripsi Membership
Andrews, jean, author
Course technology cengage learning, 2013
Buku Teks
Syngress, 2013
eBooks