@BOOK {COUPER:1993a,
title = {Consevation des sols: utilization des banquettes a double courbure: Guide de recherche de l'Iita, No. 6},
author = {Couper, D. C. },
series = {Guide de recherche de l'Iita, No. 6},
year = {1993},
month = {February},
publisher = {International Institute of Tropical Agriculture (IITA)},
address = {Ibadan, Nigeria},
note = {25p.},
}