Dimov, D., Marinov, I., Penev, T., Miteva, C., & Gergovska, Z. (2019). Animal hygienic assessment of air carbon dioxide concentration in semi-open freestall barns for dairy cows. Bulgarian Journal of Agricultural Science, 25(2), 354-362. https://agriacad.eu/ojs/index.php/bjas/article/view/4418