Geographie, Naturgeschichte und Topographie von Texas, book, 1845; (https://texashistory.unt.edu/ark:/67531/metapth28585/m1/89/: accessed July 18, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .
Geographie, Naturgeschichte und Topographie von Texas, book, 1845; (https://texashistory.unt.edu/ark:/67531/metapth28585/m1/89/: accessed July 18, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .