A. Ivanova, N. Tsvetkova, R. Harizanov, and R. Borisova, “STUDY OF THE DISTRIBUTION OF PNEUMOCYSTOSIS IN BULGARIA BETWEEN SEPTEMBER 2017 AND APRIL 2019 BY USING REAL- TIME PCR”, Probl Infect Parasit Dis, vol. 47, no. 2, pp. 24–27, Dec. 2019, doi: 10.58395/pipd.v47i2.8.