[Calvin Pigg on a Ford tractor], photograph, December 3, 1959; (https://texashistory.unt.edu/ark:/67531/metadc1486313/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
[Calvin Pigg on a Ford tractor], photograph, December 3, 1959; (https://texashistory.unt.edu/ark:/67531/metadc1486313/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .