Johnstone, Richard
Cavendish Publishing, 1997
Buku Teks
Eisenmann, Charles, author
Unesco, 1954
Buku Teks
Church, W. Lawrence, author
ELIPS II, 2002
Buku Teks
Kenny, Philip H.
Butterworth, 1994
Buku Teks
edited by Charles J. White and Norman Gross
American Bar Association , 1985
Buku Teks