Brdak, M. “Media Image of Sport Volunteering During the UEFA Euro 2012™ and the Motives for Social Work and Its Style of Volunteers Working in Poznan and in Poland”. Journal of Education, Health and Sport, vol. 5, no. 11, Nov. 2015, pp. 533-41, https://apcz.umk.pl/JEHS/article/view/3246.