Shouqin, Zhong, et al. “Temporal Variation of Soil Water and Its Influencing Factors in Hilly Area of Chongqing, China”. International Journal of Agricultural and Biological Engineering, vol. 7, no. 4, Aug. 2014, pp. 47-59, https://ijabe.migration.pkpps03.publicknowledgeproject.org/index.php/ijabe/article/view/1160.