Batyk, I. “IMPACT OF LOCAL BORDER TRAFFIC WITH THE KALININGRAD DISTRICT OF THE RUSSIAN FEDERATION IN SCOPE AND LEVEL MARKETING OF GOODS AND SERVICES”. Acta Scientiarum Polonorum. Oeconomia, Vol. 12, no. 4, Dec. 2013, pp. 5-15, https://js.wne.sggw.pl/index.php/aspe/article/view/4093.