399th Fighter Squadron emblem.
<a href="https://en.wikipedia.org/wiki/United_States_Army_Institute_of_Heraldry" class="extiw" title="en:United States Army Institute of Heraldry">en:United States Army Institute of Heraldry</a>
2017-06-16
<cite class="book" style="font-style:normal">Robertson, Bruce , ed.  (1961) <i> United States Army and Air Force Fighters 1916-1961</i>, Hertfordshire, England:  Harleyford Publishers, Lts.  <small><a href="https://en.wikipedia.org/wiki/International_Standard_Book_Number" class="extiw" title="en:International Standard Book Number">ISBN</a>:  <a href="//commons.wikimedia.org/wiki/Special:BookSources/9780900435126" title="Special:BookSources/9780900435126">9780900435126</a>. </small></cite>