Khan, M. R. Gijzen, H. J. text Dar es Salaam, Tanzania The Faculty of Science, University of Dar Es Salaam c1989 monographic viii, 382 p. : ill. edited by M. R. Khan, H. J. Gijzen Proceedings of a symposium organized by the Faculty of Science University of Dar Es Salaam, September 11-14th 1989 Environmental Technology TD187.5 .S9 1989 99878814116 UOEL 000 20170726121407.0