Texas. Legislature. House of Representatives. 80th Texas Legislature, Regular Session, House Bill 387, Chapter 609, legislative document, June 15, 2007; (https://texashistory.unt.edu/ark:/67531/metapth155316/m1/1/: accessed April 22, 2018), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .