Support ventilation versus conventional oxygen [1] (multiple letters)

Cotter, G.; Vered, Z.; Shpirer, I.; Masip, J.; Betbese, A. J.; Paez, J.; Vecilla, F.; Kelly, C.; Newby, D. E.; Boon, N. A.; Douglas, N. J.; Nava, S.; Carlucci, A.