Simeonovski, Ivan, Viktoriya Levterova, Mariya Malcheva, and Todor Kantardjiev. 2018. “GENETIC SURVEY OF INVASIVE S. PNEUMONIAE SEROTYPES IN BULGARIA FOR A 5-YEAR PERIOD”. PROBLEMS of Infectious and Parasitic Diseases 46 (2): 5-9. https://doi.org/10.58395/pipd.v46i2.17.