@BOOK {COUPER:1991a,
title = {Land survey for research stations: IITA research guide, No. 1},
author = {Couper, D. C. },
series = {IITA research guide, No. 1},
year = {1991},
month = {December},
publisher = {International Institute of Tropical Agriculture (IITA)},
address = {Ibadan, Nigeria},
note = {36p.},
}