LAZAROV, S., & ZHELYAZKOVA, I. (2018). HYGIENIC BEHAVIOUR OF BEE COLONIES AND TOTAL PROTEIN CONTENT IN THE HAEMOLYMPH OF WORKER BEES (APIS MELLIFERA L.). Bulgarian Journal of Agricultural Science, 24(Supplement 1), 156–161. https://agriacad.eu/ojs/index.php/bjas/article/view/5039