D. Eidukas, R. Labrencas, I. Grigaliūnienė, M. Skučas, and R. Lekas, “Influence of the Variability of Excitation Parameters on a Rhythm in Parasystole Mathematical Model and in Clinic”, ELEKTRON ELEKTROTECH, vol. 77, no. 5, pp. 37–40, May 2007, doi: 10.5755/j02.eie.10736.