Health & Safety Code
http://tlo2.tlc.state.tx.us/statutes/hs.toc.htm

Family Code
http://tlo2.tlc.state.tx.us/statutes/fa.toc.htm

Chapter 191, Health & Safety, Title 3, Vital Statistics
http://tlo2.tlc.state.tx.us/statutes/docs/HS/content/htm/hs.003.00.000191.00.htm

The Marriage Relationship, Family Code
http://tlo2.tlc.state.tx.us/statutes/docs/FA/content/htm/fa.001.00.000001.00.htm