GCE O level Mathematics: Lessons 6-10 / Namibia Extension Unit. - [Lusaka]: Namibia Extension Unit, 1988.
UNITED NATIONS INSTITUTE FOR NAMIBIA (UNIN)
UNITED NATIONS INSTITUTE FOR NAMIBIA (UNIN)
http://192.168.151.11//gce-o-level-mathematics-lessons-6-10-namibia-extension-unit-lusaka-namibia-extension-unit-1988
PA 4/1/6/57