BT-2B-I Douglas Observation, photograph, November 1, 1935; (https://texashistory.unt.edu/ark:/67531/metapth15642/m1/1/: accessed April 30, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .
BT-2B-I Douglas Observation, photograph, November 1, 1935; (https://texashistory.unt.edu/ark:/67531/metapth15642/m1/1/: accessed April 30, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .