Siagian, R. C., L. . Alfaris, G. N. . Ahmad, N. . Laeiq, A. C. . Muhammad, U. I. . Nyuswantoro, and B. . Nasution. “Relationship Between Solar Flux and Sunspot Activity Using Several Regression Models”. JURNAL ILMU FISIKA, vol. 15, no. 2, June 2023, pp. 146-65, doi:10.25077/jif.15.2.146-165.2023.