1. American Association of State Highway and Transportation Officials (AASHTO). AASHTO LRFD bridge design specifications. 5th ed. Washington DC, USA: AASHTO; 2010.
2. American Concrete Institute (ACI) Committee 229. Controlled low-strength materials, ACI 229R-99 Report, Farmington Hills, Michigan, USA: ACI; 1999.
3. American Water Works Association (AWWA). American national standard for polyethylene encasement for ductile iron piping for water and other liquids. ANSI/AWWA C105/A21.5-88, Denver, CO, USA: AWWA; 1988.
4. American Water Works Association (AWWA). Ductile-iron pipe and fittings, Manual of water supply practices M41. 3rd ed. Denver, CO, USA: AWWA; 2009.
5. American Water Works Association (AWWA). Installation guide for buried pipes. 5th ed. AWWA; 2016.