SEROPREVALENCE AND RISK FACTORS OF BOVINE RESPIRATORY SYNCYTIAL VIRUS IN DAIRY AND BEEF CATTLE HERDS IN REPUBLIC OF BULGARIA. tjs [Internet]. 2024 Jun. 3 [cited 2024 Sep. 15];22(1):6. Available from: https://tjs.trakia-uni.bg/index.php/tjs/article/view/2