Characteristics of patients who received helicopter emergency medical services in Japan from 2012 to 2019: a retrospective analysis of data from Tochigi Prefecture., Wake Koji;Noguchi Takafumi;Hishinuma Hidekazu;Zaitsu Masayoshi;Kikuchi Jin;Uchida Masatoshi;Hayashi Kentaro;Machida Masanari;Houzumi Hajime;Hoshiyama Eisei;Takahashi Kyo;Kobashi Gen;Ono Kazuyuki, Scandinavian journal of trauma, resuscitation and emergency medicine, 30(1), 25, 11 Apr. 2022