Markova , E., & Teofilova, T. (2011). Syrphid communitieS (Syrphidae, diptera) in baSic typeS of aGroecoSyStemS in Karlovo valley (bulGaria). Bulgarian Journal of Agricultural Science, 17(1), 49-54. https://agriacad.eu/ojs/index.php/bjas/article/view/5764