@INBOOK {SINGH:2001d, title = {Decision support systems for improving the application of integrated nutrient management technologies}, author = {Singh, U. and Diels, J. and Singh, B. and Ortiz, R. }, editor = {Tian, G. and Ishida, F. and Keatinge, J. }, series = {Vol 58}, year = {2001}, type = {Sustaining soil fertility in West Africa}, pages = {305--321}, publisher = {Soil Science of America (SSSA)}, address = {Madison, USA}, }