[Postcard from Birdie to Mrs. M. M. Matlock, February 27, 1911], postcard, February 27, 1911; (https://texashistory.unt.edu/ark:/67531/metapth752773/m1/1/: accessed September 28, 2020), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .