Al-Omran, A. M., Aly, A. A., Al-Wabel, M. I., Al-Shayaa, M. S., Sallam, A. S., & Nadeem, M. E. (2017). Geostatistical methods in evaluating spatial variability of groundwater quality in Al-Kharj Region, Saudi Arabia. Appl. Water Sci., 7, 4013–4023.