Surikova, Valentīna, and Aldis Kārkiņš. “COMPETITION BETWEEN APPLE-TREES AND GRASS IN THE ORCHARD”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (August 3, 2015): 169–175. Accessed May 4, 2024. https://journals.ru.lv/index.php/ETR/article/view/1118.