1. Foltran F, Ballali S, at al. Foreign bodies in the airways: a meta-analysis of published papers. Int J Pediatr Otorhinolaryngol. 2012 May 14;76 Suppl 1:S12-9.
2. Sidell DR, KimI A, Coker TR, et al.Food choking hazards in children[J].Int J Pediatr Otorhinolaryngol, 2013,77(12):1940-1946.