Soil Survey of Callahan County, Texas, book, 1981; (https://texashistory.unt.edu/ark:/67531/metapth130206/m1/1/: accessed May 11, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .
Soil Survey of Callahan County, Texas, book, 1981; (https://texashistory.unt.edu/ark:/67531/metapth130206/m1/1/: accessed May 11, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .