Scherr, Sara J. On-farm research : the challenges of agroforesrty / Sara J. Sc herr. - Nairobi : International Council for Research in Agroforestry, 1992. - 110 p ; 24 cm. - ICRAF Reprint ; no. 89 . Reprinted from Agroforestry Systems, 15: 95-110, 1991. Includes bibliographical references. Subjects--Topical Terms: Agroforestry -- Research -- On-farm.