McDonald, Robert L.
Addison-Wesley, 2006
Buku Teks
McDonald, Robert L.
Pearson Education, 2006
Multimedia
Georgiev, Vassil St.
Krager, 1983
Buku Teks SO
London: Tiger Books International, 1994,
Buku Referensi
edited by Jack Clark Frances, Joyce A. Frost and J. Gregg Whittaker
McGraw-Hill, [Date of publication not identified]
Buku Referensi