Clark, Joe. [Slingshot John Milligan Scrambling an Egg resting on Joe Clark's Hand (4)], photograph, January 17, 1961; (https://texashistory.unt.edu/ark:/67531/metadc499115/m1/1/: accessed December 11, 2018), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .