Influenza outbreak in a Kansas military camp.
Unknown author<span style="display: none;">Unknown author</span>
CC BY 4.0
<a rel="nofollow" class="external free" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181817/">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181817/</a>