1. British thoracic society guidelines on diagnostic flexible bronchoscopy;Thorax,2001
2. Postal survey of bronchoscopic practice by physicians in the United Kingdom;Simpson;Thorax,1986
3. Complications of transbronchial lung biopsies;Herf;Chest,1978
4. HCUP state inpatient databases (SID);Healthcare Cost and Utilization Project (HCUP),2000-2009
5. HCUP state ambulatory surgery databases (SASD);Healthcare Cost and Utilization Project (HCUP),2000-2009