4Kingston GW,Phang PT,Leathley MJ. Increased incidence of nosocomial pneumonia in mechanically ventilated patients with subclincal aspiration. Am J Surg,1991,161(5): 589- 592.
5Grap MJ,Munro CL. Ventilator- associated pneumonia: clinical significance and implications for nursing. Heart Lung,1997,26(6): 419- 429.
