@BOOKLET {WARREN:1992,
title = {A preliminary analysis of indigenous soil classification and management systems in four ecozones of Nigeria},
author = {Warren, D. M. },
year = {1992},
address = {International Institute of Tropical Agriculture (IITA)},
howpublished = {Resource and Crop Management Division (RCMD) Discussion paper 92/1. 30p.},
note = {30p.},
}