@BOOK {COUPER:1995b, title = {Farm records and work planning on agricultural research farms: IITA research guide, No. 18}, author = {Couper, D. C. }, series = {IITA research guide, No. 18}, year = {1995}, month = {July}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, note = {18p.}, }