Guan, Yi, Amber Farooqui, Huachen Zhu, Wei Dong, Jia Wang, and David J Kelvin. “H7N9 Incident, Immune Status, the Elderly and a Warning of an Influenza Pandemic”. The Journal of Infection in Developing Countries 7, no. 04 (April 17, 2013): 302–307. Accessed April 28, 2024. https://jidc.org/index.php/journal/article/view/23592638.