Words and phrases : legally defined, third edition, volume 3
under the general editorship of John B. Saunders
Butterworth, 1989
 Buku Referensi
Words and phrases : legally defined, third edition, volume 1
under the general editorship of John B. Saunders
Butterworth, 1988
 Buku Referensi
Words and phrases : legally defined, third edition, volume 4
under the general editorship of John B. Saunders
Butterworth, 1990
 Buku Referensi
Words and phrases : legally defined
David Hay
London : Routterworths, 1993,
 Buku Referensi
Encyclopedia of educational research : sixth edition, volume 2
Marvin C. Alkin, editor-in-chief
MacMillan Library Reference USA, 1992
 Buku Referensi