Ahmed, Abdullah K., and Zahraa Adnan. “Photometric Investigations of NGC 2577 and NGC 4310 Lenticular Galaxies”. Iraqi Journal of Science 59, no. 2C (June 27, 2018): 1129-1138. Accessed December 3, 2021. https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/332.