BLAŠKO, Michal a Pavlína SONNKOVÁ. Problems with the Involvement of Accommodation Providers in Domestic Tourism in Destination Card Systems. Online. In Petříček, M; Hán, J.; Komínková, B.; Balakovská, R. Current trends in spas, hospitality and tourism „Tourism digitalization“. 10. vyd. Praha: Vysoká škola hotelová a ekonomická Praha, 2022, s. 44-54. ISBN 978-80-7632-076-5.