Columbia subject headings:
Harvard subject headings:
Delaware River Valley (N.Y.-Del. and N.J.)
Delaware River Watershed (N.Y.-Del. and N.J.)
Valley ecology--Delaware River Valley (N.Y.-Del. and N.J.)
Water resources development--Environmental aspects--Delaware River Valley (N.Y.-Del. and N.J.)
Watershed ecology--Delaware River Watershed (N.Y.-Del. and N.J.)
Watershed restoration--Delaware River Watershed (N.Y.-Del. and N.J.)
Princeton subject headings:
Delaware River Valley (N.Y.-Del. and N.J.)
Valley ecology--Delaware River Valley (N.Y.-Del. and N.J.).
Water resources development--Environmental aspects--Delaware River Valley (N.Y.-Del. and N.J.).