ČEKEREVAC, Zoran - DVOŘÁK, Zdeněk - PRIGODA, Ludmila - ČEKEREVAC, Petar. Risks of bitcoin virtual currency. In Communications : scientific letters of the University of Žilina. - Žilina : University of Žilina, 2015. ISSN 1335-4205, 2015, vol. 17, no. 1, s. 93-98.