An Investigation of Accidental Ingestion and Aspiration in Dental Practice at Nippon Dental University Hospital-A 13-year Institutional Review of Incident Reports-
Fields, R. T. and Schow, S. R. : Aspiration and ingestion of foreign bodies in oral and maxillofacial surgery : a review of the literature and report of five cases, J. Oral Maxillofac. Surg., 56 : 1091~1098, 1998.