U.S. Federal Water Pollution Control Administration, Division of Technical Support; [for sale by the Supt. of Docs., U.S. Govt. Print. Off.]1969.<NA217-42>
[by] Kenneth M. MackenthunU.S. Federal Water Pollution Control Administration, Division of Technical Support; [for sale by the Supt. of Docs., U.S. Govt. Print. Off.]1969