Sun, Y., Xu, Q., Shen, Y., Liu, L., Wei, K., Sun, H., Pu, J., Chang, K.-C., & Liu, J. (2014). Naturally Occurring Mutations in the PA Gene Are Key Contributors to Increased Virulence of Pandemic H1N1/09 Influenza Virus in Mice. Journal of Virology, 88(8), 4600-4604. https://doi.org/10.1128/jvi.03158-13