Taseva, Evgeniya, et al. “IS THERE AN OUTBREAK OF TICK-BORNE ENCEPHALITIS IN PERNIK DISTRICT, BULGARIA? FOUR CASES REGISTERED FOR A PERIOD OF FOUR YEARS – CLINICAL MANIFESTATIONS AND EPIDEMIOLOGICAL RELATIONS”. PROBLEMS of Infectious and Parasitic Diseases, vol. 49, no. 1, Apr. 2021, pp. 19-25, https://doi.org/10.58395/pipd.v49i1.57.