Texas. Legislature. House of Representatives. 80th Texas Legislature, Regular Session, House Bill 12, Chapter 1159, legislative document, 2007-05/2007-06; (https://texashistory.unt.edu/ark:/67531/metapth154695/m1/1/: accessed October 19, 2018), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .