@BOOK {SCHULZ:2000, title = {Farmer participation in research and development; the problem census and solving technique: IITA research guide, No. 57}, author = {Schulz, S. }, series = {IITA research guide, No. 57}, year = {2000}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, isbn = {978-131-172-X}, note = {22p.}, }