Roudsari BS, Nathens AB, Arreola-Risa C, Cameron P, Civil I, Grigoriou G, Gruen RL, Koepsell TD, Lecky FE, Lefering RL, Liberman M, Mock CN, Oestern HJ, Petridou E, Schildhauer TA, Waydhas C, Zargar M, Rivara FP. Emergency Medical Service (EMS) systems in