The Oklahoma Labor Unit (Oklahoma City, Okla.), Vol. 1, No. 41, Ed. 1 Saturday, April 3, 1909, newspaper, April 3, 1909; (https://gateway.okhistory.org/ark:/67531/metadc107612/m1/7/: accessed April 24, 2024), University of North Texas Libraries, The Gateway to Oklahoma History, gateway.okhistory.org; .