Efficacy of the EZ-IO (R) needle driver for out-of-hospital intraosseous access - a preliminary, observational, multicenter study - Schalk, Richard; Schweigkofler, Uwe; Lotz, Gösta; Zacharowski, Kai; Latasch, Leo; Byhahn, Christian (Scandinavian journal of trauma, resuscitation and emergency medicine, 2011)