Arnull, Anthony
Leicester University Press, 1990
Buku Teks
Panesar, Sukhninder, author
Longman, 2001
Buku Teks
Cunningham, James P., author
Kogan Page, 1973
Buku Teks
Lucas, John, author
Cassell, 1980
Buku Referensi
Cabanellas, Guillermo, author
VCH, 1991
Buku Teks