Johann Radon, Austrian mathematician, memorial at <a href="//commons.wikimedia.org/wiki/Category:University_of_Vienna" title="Category:University of Vienna">University of Vienna</a>
<a href="//commons.wikimedia.org/wiki/User:Arved" title="User:Arved">Arved</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>