Syrjänen, R. K., Jokinen, J., Ziegler, T., Sundman, J., Lahdenkari, M., Julkunen, I., & Kilpi, T. M. (2014). Effectiveness of Pandemic and Seasonal Influenza Vaccines in Preventing Laboratory-Confirmed Influenza in Adults: A Clinical Cohort Study during Epidemic Seasons 2009–2010 and 2010–2011 in Finland. Public Library of Science.

Syrjänen, Ritva K., Jukka Jokinen, Thedi Ziegler, Jonas Sundman, Mika Lahdenkari, Ilkka Julkunen, and Terhi M. Kilpi. Effectiveness of Pandemic and Seasonal Influenza Vaccines in Preventing Laboratory-Confirmed Influenza in Adults: A Clinical Cohort Study During Epidemic Seasons 2009–2010 and 2010–2011 in Finland. Public Library of Science, 2014.

Syrjänen, Ritva K., et al. Effectiveness of Pandemic and Seasonal Influenza Vaccines in Preventing Laboratory-Confirmed Influenza in Adults: A Clinical Cohort Study During Epidemic Seasons 2009–2010 and 2010–2011 in Finland. Public Library of Science, 2014.