@BOOK {KANG:1996a, title = {Sustainable agroforestry systems for the tropics; concepts and examples: IITA research guide, No. 26}, author = {Kang, B. T. }, series = {IITA research guide, No. 26}, year = {1996}, month = {October}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, note = {25p.}, }