@INPROCEEDINGS {SPENCER:1991c, title = {Development of technologies for productive and sustainable agriculture for the humid and sub-humid tropics of Africa}, author = {Spencer, D. and Mulongoy, K. }, booktitle = {The role of biology in resolving the food crisis in Africa, edited by A.T. Ba and M. Ndoye. Proceedings, International Symposium, Jul 1989, Yamoussoukro, Cote d'Ivoire}, year = {1991}, pages = {133--143}, publisher = {ICSU; UNDP; UNESCO}, address = {Paris, France}, }