Govender, Paulene, and Venkataraman Sivakumar. “Investigating Diffuse Irradiance Variation under Different Cloud Conditions in Durban, Using K-Means Clustering”. Journal of Energy in Southern Africa, vol. 30, no. 3, Sept. 2019, pp. 22-32, doi:10.17159/2413-3051/2019/v30i3a6314.