2) Christpher K.L., Spofford B.T., Brannin P.K. et al.: Transtracheal oxygen therapy for refractory hypoxemia, JAMA, 254: 494~497, 1986.
3) Christpher K.L., Spofford B.T., Petrun M.D. et al.: A program for transtracheal oxygen delivery assessment of safety and efficacy, Ann Int Med, 107: 802~808, 1987.
4) Heimlich H.J., Car G.C.: The micro-trach, a seven-year experience with transtracheal oxygen therapy, Chest, 95: 1008~1012, 1989.