Bozhkova, Martina, Teodora Kalfova, Steliyan Petrov, Tanya Velyanova, Hristo Taskov, Maria Nikolova, and Marianna Murdjeva. “ASSESSMENT OF SARS-COV-2 SPECIFIC B-CELL IMMUNE MEMORY: EVIDENCE FOR PERSISTENCE UP TO 1 YEAR POST-INFECTION”. PROBLEMS of Infectious and Parasitic Diseases 50, no. 3 (August 14, 2023): 14–18. Accessed June 9, 2025. https://pipd.ncipd.org/index.php/pipd/article/view/50-3-2-assessment-of-sars-cov-2.