Grzelak, M., and E. Roszko-Wójtowicz. “DEVELOPMENT OF POLISH FOREIGN TRADE IN AGRI-FOOD PRODUCTS AFTER POLAND'SACCESSION TO THE EU”. Acta Scientiarum Polonorum. Oeconomia, Vol. 14, no. 4, Dec. 2015, pp. 37-48, https://js.wne.sggw.pl/index.php/aspe/article/view/4196.