Black Hand members at Topčider Park.
Unknown author<span style="display: none;">Unknown author</span>
<a rel="nofollow" class="external text" href="https://www.warhistoryonline.com/articles/the-shots-that-started-world-war-one-the-conspiracy-and-belgrade-part-2-by-james-lyon-phd.html">The Shots That Started World War One: The Conspiracy And Belgrade (Part 2) – By James Lyon, PhD.</a>. War History Online.