Geology of the forty-ninth parallel sheet no. 6, map 79 A., map, 1913; (https://texashistory.unt.edu/ark:/67531/metapth187400/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Geology of the forty-ninth parallel sheet no. 6, map 79 A., map, 1913; (https://texashistory.unt.edu/ark:/67531/metapth187400/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .