430 _ 0
‡a
Ecological research (Washington, D.C.)
430 _ 0
‡a
Ecological research series
410 1 _
‡a
United States.
‡b
Environmental Protection Agency.
‡b
Office of Research and Development.
‡t
Research reporting series.
‡n
3,
‡p
Ecological research
410 1 _
‡a
United States.
‡b
Environmental Protection Agency.
‡b
Office of Research and Monitoring.
‡t
Ecological research.