@BOOK {SMITH:1995a, title = {Caracterisation socio-economique des environnments et des technologies: Guide de recherche de l'Iita, No. 50}, author = {Smith, J. }, series = {Guide de recherche de l'Iita, No. 50}, year = {1995}, month = {March}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, note = {37p.}, }