Casler, Howard M. The Oklahoma Labor Unit (Oklahoma City, Okla.), Vol. 3, No. 1, Ed. 1 Saturday, June 17, 1911, newspaper, June 17, 1911; (https://gateway.okhistory.org/ark:/67531/metadc106995/m1/1/: accessed February 21, 2019), University of North Texas Libraries, The Gateway to Oklahoma History, gateway.okhistory.org; .