The Civil service year book 1988
England. Cabinet Office
Her Majesty's Stationery Office, 1988
 Buku Referensi
The hospitals and health services year book 1989
editor, NW Chaplin
The Ynstitute of Health Services Management, 1989
 Buku Referensi
The British year book of international law 1989 : sixtieth year of issue
Clarendon Press, 1990
 Buku Referensi
The Computer users year book 1989 : installations, volume 3
VNU Business Publications, 1989
 Buku Referensi
The Computer users year book 1989 : services, volume 2
VNU Business Publications, 1989
 Buku Referensi