Emergency Medical Service (EMS) systems in developed and developing countries - 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, H-J; Petridou, E; Schildhauer, TA; Waydhas, C; Zargar, M; Rivara, FP (Injury, 2007)