Bolan, H. W.; Benson, E. E.; Hobbs, O. K. & Van Lith, P. American expeditionary forces H.Q. 306th Tank Corps. Reconnaaissance Dept., Vauquois Hill, 4 kilometers S.E. of Varennes, France., map, January 27, 1919; (https://texashistory.unt.edu/ark:/67531/metapth493473/m1/1/: accessed June 15, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .