Walski, Thomas M. (March 2006), "A history of water distribution", Journal of the American Water Works Association, 98 (3), American Water Works Association: 110–121, doi:10.1002/j.1551-8833.2006.tb07611.x, S2CID108604497, p. 112.
Walski, Thomas M. (March 2006), "A history of water distribution", Journal of the American Water Works Association, 98 (3), American Water Works Association: 110–121, doi:10.1002/j.1551-8833.2006.tb07611.x, S2CID108604497, p. 112.