21st Contracting 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>
2019-07-08
<a rel="nofollow" class="external free" href="https://www.peterson.af.mil/About/Fact-Sheets/Display/Article/326207/21st-contracting-squadron/">https://www.peterson.af.mil/About/Fact-Sheets/Display/Article/326207/21st-contracting-squadron/</a>