Wojciechowska-Solis, J., A. Mazurek-Kusiak, and A. Soroka. “THE INFLUENCE OF SPECIALIZED TRAINING ON THE QUALITY OF HOTEL CUSTOMERS SERVICE”. Acta Scientiarum Polonorum. Oeconomia, Vol. 15, no. 2, June 2016, pp. 173-85, https://js.wne.sggw.pl/index.php/aspe/article/view/4234.