Boumahdi, Rachid, Omar Kihel, and Sukrawan Mavecha. “Proof of the Conjecture of Keskin, Siar and Karaatli”. Annales Fennici Mathematici 43, no. 1 (February 1, 2018): 557–561. Accessed April 16, 2025. https://afm.journal.fi/article/view/135744.