CDC article Update: Influenza Activity—United States and Worldwide, 2003–04 Season, and Composition of the 2004–05 Influenza Vaccine published 2 July 2004
Jilani TN, Jamil RT, Siddiqui AH (November 30, 2020). "H1N1 Influenza". H1N1 Influenza in StatPearls. StatPearls. PMID30020613. Archived from the original on 12 March 2020. Retrieved 25 August 2020.
Jilani TN, Jamil RT, Siddiqui AH (November 30, 2020). "H1N1 Influenza". H1N1 Influenza in StatPearls. StatPearls. PMID30020613. Archived from the original on 12 March 2020. Retrieved 25 August 2020.
Jilani TN, Jamil RT, Siddiqui AH (November 30, 2020). "H1N1 Influenza". H1N1 Influenza in StatPearls. StatPearls. PMID30020613. Archived from the original on 12 March 2020. Retrieved 25 August 2020.