Nalitov VN.
Med Sestra. 1974 Aug;33(8):39-42.
PMID: 4499561

Popova TP.
Feldsher Akush. 1979 Mar;44(3):52-5.
PMID: 255128

Nagel EL.
Emerg Med Serv. 1977 Jan-Feb;6(1):52.
PMID: 10235996

Sefrin P, Kuhnigk H.
Anasthesiol Intensivmed Notfallmed Schmerzther. 2006 Jan;41(1):2-8. doi: 10.1055/s-2006-924965.
PMID: 16440252

Girdley FM, Stone HL, Birnbaum ML, Raabe K.
J Allied Health. 1983 Feb;12(1):56-63.
PMID: 6841271

Nagel EL.
Emerg Med Serv. 1975 Mar-Apr;4(2):60-1.
PMID: 10237394

[No authors listed]
JEMS. 2013 Dec;38(12):10.
PMID: 24592559