Caeilli, William, author
Macmillan, 1991
Buku Teks
Sorenson, Ritch, author
Prentice-Hall, 2001
Buku Referensi
edited by Jan van Leeuwen
Elsevier, 1990
Buku Referensi
edited by Jan van Leeuwen
Elsevier, 1990
Buku Referensi
Stallings, William, author
Howard W. Sams & Company, 1989
Buku Referensi