Effect of Total, Northern and Southern Hemisphere Sunspot Number (Ri, Rn and Rs) on F2- Layer Critical Frequencies at Mid- Latitude Rome Station During the Descending Phase of Solar Cycle 23. Iraqi Journal of Science. 2023;57(3A):2063-2074. Accessed July 3, 2024. https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/9962