@BOOK {COUPER:1994, title = {Land clearing for agricultural research stations: IITA research guide, No. 5}, author = {Couper, D. C. }, series = {IITA research guide, No. 5}, year = {1994}, month = {March}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, note = {17p.}, }