Sawicki, J., M. Konopka, and M. Modzelewski. “Narrow QRS Complex Tachycardia ? Atrial Fibrillation, Atrial Flutter or Atrial Tachycardia?”. Medycyna Faktow (J EBM), Vol. 9, no. 1(30), Mar. 2016, pp. 80-82, https://www.journalsmededu.pl/index.php/jebm/article/view/2275.