The Roentgen rays, their production and use.

Plates printed on both sides.

Strategic plan for the ecological resources of Illinois.

"Gretchen Bonfert, Green Strategies, Springfield, Illinois, compiled this strategic plan and convened the public meetings whereby participants contributed to the plan."-- p. ii.

Pulpwood production and consumption in the North Central Region, by county, 1967.

Cover title.

The ecological impact of synthetic organic compounds on esturine ecosystems /

Subject Profile Index: p.169-353.