The river basin model:
economic sector.
By Envirometrics, inc., for the Office of Research and Monitoring, Environmental Protection Agency.

APA Citation

Envirometrics, i., United States. Environmental Protection Agency. Office of Research and Monitoring. (1971). The river basin model: economic sector. Washington: [U.S. Environmental Protection Agency] For sale by the Supt. of Docs., U.S. Govt. Print. Off..

MLA Citation

Envirometrics, inc, and United States. Environmental Protection Agency. Office of Research and Monitoring. The River Basin Model: Economic Sector. Washington: [U.S. Environmental Protection Agency] For sale by the Supt. of Docs., U.S. Govt. Print. Off., 1971.