Yap, Florence H. Y.; Ho, Pak-Leung; et al. (June 2004). "Excess hospital admissions for pneumonia, chronic obstructive pulmonary disease, and heart failure during influenza seasons in Hong Kong". Journal of Medical Virology. 73 (4): 617–623. doi:10.1002/jmv.20135. PMID15221909. S2CID35385523.
Yap, Florence H. Y.; Ho, Pak-Leung; et al. (June 2004). "Excess hospital admissions for pneumonia, chronic obstructive pulmonary disease, and heart failure during influenza seasons in Hong Kong". Journal of Medical Virology. 73 (4): 617–623. doi:10.1002/jmv.20135. PMID15221909. S2CID35385523.
Yap, Florence H. Y.; Ho, Pak-Leung; et al. (June 2004). "Excess hospital admissions for pneumonia, chronic obstructive pulmonary disease, and heart failure during influenza seasons in Hong Kong". Journal of Medical Virology. 73 (4): 617–623. doi:10.1002/jmv.20135. PMID15221909. S2CID35385523.