[Front view of a scale model of the H-40], photograph, June 12, 1958; (https://texashistory.unt.edu/ark:/67531/metadc950176/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
[Front view of a scale model of the H-40], photograph, June 12, 1958; (https://texashistory.unt.edu/ark:/67531/metadc950176/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .