Boostani, H. R., & ronaghi, A. "Investigation of Some Nutrients Concentration and Corn Yield with Application of Different Sewage Sludge Levels and Chemical Fertilizer in Three Textural Classes of a Calcareous Soil", Water and Soil, 26, 5, 2012, 1092–1100. doi: 10.22067/jsw.v1391i0.16921