{{Cite journal| doi = 10.1186/s13049-021-00898-y| issn = 1757-7241 (Electronic) 1757-7241 (Linking)| volume = 29| issue = 1| pages = 92| last1 = Pietsch| first1 = U.| last2 = Knapp| first2 = J.| last3 = Mann| first3 = M.| last4 = Meuli| first4 = L.| last5 = Lischke| first5 = V.| last6 = Tissi| first6 = M.| last7 = Sollid| first7 = S.| last8 = Rauch| first8 = S.| last9 = Wenzel| first9 = V.| last10 = Becker| first10 = S.| last11 = Albrecht| first11 = R.| title = Incidence and challenges of helicopter emergency medical service (HEMS) rescue missions with helicopter hoist operations: analysis of 11,228 daytime and nighttime missions in Switzerland| journal = Scand J Trauma Resusc Emerg Med| date = 2021-07-14| pmid = 34253244}}