Kacprzak, M., and T. Mikulska. “FRANCHISING IN TOURISM ON EXAMPLE OF THE TUI TRAVEL AGENCY”. Acta Scientiarum Polonorum. Oeconomia, Vol. 7, no. 2, June 2008, pp. 23-35, https://js.wne.sggw.pl/index.php/aspe/article/view/3775.