Duangporn Sansanasupapong และ Ratana Somrongthong. (2011) Perception and willingness to obtain influenza vaccination among healthcare staff and elderly group : a case study at the public hospital, Nakhonchaisri District Nakhonpathom Province. Chulalongkorn University:ม.ป.ท.Duangporn Sansanasupapong และ Ratana Somrongthong. 2011. Perception and willingness to obtain influenza vaccination among healthcare staff and elderly group : a case study at the public hospital, Nakhonchaisri District Nakhonpathom Province. ม.ป.ท.:Chulalongkorn University;Duangporn Sansanasupapong และ Ratana Somrongthong. Perception and willingness to obtain influenza vaccination among healthcare staff and elderly group : a case study at the public hospital, Nakhonchaisri District Nakhonpathom Province. ม.ป.ท.:Chulalongkorn University, 2011. Print.