Boufekane, A., and O. Saighi. “Kriging Method of Study of the Groundwater Quality Used for Irrigation - Case of Wadi Djendjen Plain (North-East Algeria)”. Journal of Fundamental and Applied Sciences, vol. 8, no. 2, May 2016, pp. 346-62, doi:10.4314/jfas.v8i2.12.