@BOOK {STOORVOGEL:1991,
title = {The identification of agro-ecological zones for cassava in Africa with particular emphasis on soils: COSCA working paper, No. 5},
author = {Stoorvogel, J. and Fresco, L. },
series = {COSCA working paper},
year = {1991},
number = {5},
publisher = {International Institute of Tropical Agriculture (IITA)},
address = {Ibadan, Nigeria},
note = {RTB; Root and Tuber; Cassava.; 5p.},
}