@article{paperid:1053936, author = {Ovisy, Mohammad and Ahmadi Shadmehri, Mohammad Taher}, title = {Studying the changes of environmental Indicators after applying fertilizer subsidy policies at farm land in Iran: a positive mathematical programming approach}, journal = {International Journal of Academic Research}, year = {2015}, volume = {7}, number = {1}, month = {January}, issn = {2075-4124}, pages = {417--423}, numpages = {6}, keywords = {subsidies; policies; fertilizer; nitrate pollution; environmental indicators}, }