Do organic amendments improve yield trends and profitability in intensive rice systems? - Dawe, D.; Dobermann, A.; Ladha, J.K.; Yadav, R.L.; Bao, Lin; Gupta, R.K.; Lal, P.; Panaullah, G.; Sariam, O.; Singh, Y.; Swarup, A.; Zhen, Q.-X. (Elsevier, 2003)