Media type: E-Article Title: The role of on-farm trails in the evaluation of composite technologies: The case of alley farming in Southern Nigeria Contributor: Atta-Krah, A.N.; Francis, P.A. Published: Elsevier BV, 1987 Published in: Agricultural Systems, 23 (1987) 2, Seite 133-152 Language: English DOI: 10.1016/0308-521x(87)90091-6 ISSN: 0308-521X Origination: Footnote: