Harold Farnsworth Gray, Sewerage in Ancient and Medieval
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Harold Farnsworth Gray, "Sewerage in Ancient and Medieval Times," Sewage Works Journal, Volume 12, No. 5 (Sept. 1940), pp. 939 - 946. Reprinted with permission from Sewage Works Journal. Copyright 1940 Water Environment Federation, Alexandria, VA.
Harold Farnsworth Gray, "Sewerage in Ancient and Medieval Times," Sewage Works Journal, Volume 12, No. 5(Sept. 1940), pp. 939 - 946. Reprinted with permission from Sewage Works Journal. Copyright 1940 Water