Marchev, Dragomir, Borislav Borisov, Nataliya Pavlova, Sunay Ibryamov, Teodora Atanasova, Galina Yordanova, Alex Georgiev, and Samuil Petrov. “TEN YEARS OF ASTRONOMICAL OBSERVATORY AT SHUMEN UNIVERSITY”. KNOWLEDGE - International Journal 72, no. 3 (October 6, 2025): 313–318. Accessed June 5, 2026. https://ojs.ikm.mk/index.php/kij/article/view/7851.