Kamm, Antony, author
Harper Collins Pub., 1993
Buku Referensi
Collins, Carol
HarperCollins, 1995
Multimedia
edited by Lord Collins of Mapesbury ... [and others]
Sweet & Maxwell , 2006
Buku Teks
Collin, Roger R
CCH Australia, 1998
Buku Teks
Harper Collins Publishers, 2003
Buku Referensi