3Freeman J,et al.Differential risks of nosocomial infection. The American Journal of Medicine . 1981
4Gaunt PN,et al.Computer and hospital infections. Journal of Hospital Infection . 1987
5Haley RW,et al.CDC--SENIC planning committee; Study on the Efficacy of Nosocomial Infection Control (SENIC projest): Summary of study design. American Journal of Epidemiology . 1980
6Hooton TM. et al.The joint associations of multiple risk factors with the occurrence of nosocomial infection. The American Journal of Medicine . 1981
