@INBOOK {COBBINA:1991, title = {Methodological and analytical issues in on-farm alley farming research}, author = {Cobbina, J. and Atta-Krah, A. N. }, year = {1991}, type = {On-farm research in theory and practice, edited by H.J.W. Mutsaers and P. Walker}, pages = {76--82}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, }