Hospitalized Patients with 2009 H1N1 Influenza in the United States, April–June 2009Seema Jain, Lyn Finelli, Sonja J. Olsen et al.|New England Journal of Medicine|2009Cited by 1.7k
H1N1 2009 influenza virus infection during pregnancy in the USADenise J. Jamieson, Sonja J. Olsen, Daniel Kuhles et al.|The Lancet|2009Cited by 1.4k