Niţă, S., L. D. Niţǎ, C. Mihuţ, E. Kocis, L. Panaitescu, and M. Lungu. “Ecologic and Biologic Agricultural Systems”. Review on Agriculture and Rural Development, vol. 3, no. 1, Jan. 2014, pp. 338-43, https://iskolakultura.hu/index.php/rard/article/view/13445.