Valves. (2005, March 12). Retrieved November 9, 2026, from http://www.essayworld.com/essays/Valves/23580
"Valves." Essayworld.com. Essayworld.com, 12 Mar. 2005. Web. 9 Nov. 2026. <http://www.essayworld.com/essays/Valves/23580>
"Valves." Essayworld.com. March 12, 2005. Accessed November 9, 2026. http://www.essayworld.com/essays/Valves/23580.
"Valves." Essayworld.com. March 12, 2005. Accessed November 9, 2026. http://www.essayworld.com/essays/Valves/23580.