J, Razali, et al. “Probable Maximum Precipitation Comparison Using Hershfield’s Statistical Method and Hydro-Meteorological Method for Sungai Perak Hydroelectric Scheme”. International Journal of Engineering & Technology, vol. 7, no. 4.35, Nov. 2018, pp. 603-8, https://doi.org/10.14419/ijet.v7i4.35.22922.