Perfanova, Jonita, and Ivanka Lyubenova. 2017. “Distribution of the Main Groups of Soil Microorganisms in Typical Chernozem - Karasuluk (Pellic Endoclacic Vertisol (Aric Humic))”. Bulgarian Journal of Soil Science, Agrochemistry and Ecology 51 (2): 30-37. https://agriacad.eu/ojs/index.php/bjssae/article/view/1941.