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2. American Society for Testing and Materials (ASTM). (1999). “Standard guide for use of maxi-horizontal directional drilling for placement of polyethylene pipe or conduit under obstacles including river crossings.” F 1962-99 West Conshohocken Pa.
3. American Water Works Association (AWWA). (1983). “Glass-fiber-reinforced thermosetting-resin pressure pipe.” C950-81 Approved January 25 1981; Addendum C950a-83 Approved January 30 1983 Denver.