9Askarian M ,Gooran N R. National nosocomial infection surveillance system-based study in Iran : additional hospital stay attribuable to nosocomial infections [J]. Am J Infect Control, 2003, 31(8): 465-468.
10Warren DK, Shukla SJ, Olsen MA, et al. Outcome and attributable cost of ventilator-associated pneumonia among intensive care unit patients in a suburban medical center[J]. Crit Care Med, 2003, 31 (5): 1312-1317.
