@BOOK {HARTLEY:1996, title = {Irrigation systems for research farms: IITA research guide, No. 14}, author = {Hartley, P. V. }, series = {IITA research guide, No. 14}, year = {1996}, edition = {2nd. ed}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, note = {18p.}, }