Yekzaban, A. ., M. . Shabanpour, and N. . Davatgar. “Identify Effective Auxiliary Variables in Cokriging Method to Estimate Spatial Variability of Infiltration Rate”. Agricultural Advances, vol. 3, no. 6, June 2014, pp. 186-93, http://sjournals.com/index.php/aa/article/view/708.