Source: https://www.researchgate.net/profile/Stephan_Gehring/publication/258037043_The_2009_pandemic_influenza_AH1N1_coincides_with_changes_in_the_epidemiology_of_other_viral_pathogens_causing_acute_respiratory_tract_infections_in_children/links/586251ed08aebf17d3953e53/The-2009-pandemic-influenza-AH1N1-coincides-with-changes-in-the-epidemiology-of-other-viral-pathogens-causing-acute-respiratory-tract-infections-in-children.pdf