This system will be undergoing maintenance March 8th between 8:00AM and 11:00AM CST.

Smithers, W. D. (Wilfred Dudley), 1895-1981. The border air patrol 1918-1919. Picture, artwork, 1920; (https://texashistory.unt.edu/ark:/67531/metapth11931/m1/1/: accessed March 8, 2021), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .