Leszczyński, G., and M. Zieliński. “KNOWLEDGE SHARING AND BUSINESS TOURISM PRODUCTS : CASE OF INDUSTRIAL TRADE FAIRS”. Acta Scientiarum Polonorum. Oeconomia, Vol. 14, no. 2, June 2015, pp. 85-94, https://js.wne.sggw.pl/index.php/aspe/article/view/4169.