Kopeva, D., D. Blagoev, N. Sterev, and P. Zhelev. “ASSESSMENT OF DYNAMIC GROWTH OF FOOD PRODUCTION IN BULGARIA”. Acta Scientiarum Polonorum. Oeconomia, vol. 14, no. 1, Mar. 2015, pp. 55-67, https://aspe.sggw.edu.pl/article/view/461.