Tsonkova, Eva, and Nikola Sabev. “STRUCTURE OF MORBIDITY OF COVID 19 AMONG PEDIATRIC PATIENTS IN PEDIATRIC DEPARTMENT IN UNIVERSITY MULTIPROFILE HOSPITAL ACTIVE TREATMENT ‘ KANEFF’ JSC, RUSE, BULGARIA”. KNOWLEDGE - International Journal , vol. 57, no. 4, Mar. 2023, pp. 585-9, https://ikm.mk/ojs/index.php/kij/article/view/6034.