Description of Emergency Medical Services, treatment of cardiac arrest patients and cardiac arrest registries in Europe oleh Ingvild B. M. Tjelmeland, Siobhan Masterson, Johan Herlitz, Jan Wnent, Leo Bossaert, Fernando Rosell-Ortiz, Kristin Alm-Kruse, Berthold Bein, Gisela Lilja, Jan-Thorsten Gräsner, on behalf of GL2020 Epidemiology group and participating countries