Ivanova, A. et al. 2019. STUDY OF THE DISTRIBUTION OF PNEUMOCYSTOSIS IN BULGARIA BETWEEN SEPTEMBER 2017 AND APRIL 2019 BY USING REAL- TIME PCR. PROBLEMS of Infectious and Parasitic Diseases. 47, 2 (Dec. 2019), 24–27. DOI:https://doi.org/10.58395/pipd.v47i2.8.