Texas. Legislature. House of Representatives. 81st Texas Legislature, Regular Session, House Bill 963, Chapter 616, legislative document, June 19, 2009; (https://texashistory.unt.edu/ark:/67531/metapth149043/m1/1/: accessed June 19, 2019), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .