The need for, structure, and possible functions of a geographic data-base in the process of technology transfer to the small farmer
Consistent policy formulation within a skewed farm size distribution: the small farmer in Latin America
VA mycorrhiza management : a new, low cost, biological technology for crop and pasture production on infertile soils
The biology and control of purple nutsedge (Cyperus rotundus L.): Study guide to be used as a supplement to the Audiotutorial Unit in the same topic
Practicas de manejo del hato de cria en las sabanas bien drenadas de Colombia y Venezuela: Guia de estudio