Infirmities of per capita national income estimates when employed to compare levels of living between developed and retarded areas.

Mode of access: Internet.

Determination of maximum permissible levels of selected chemicals that exert toxic effects on plants of economic importance in Illinois,

Bibliographical references.

Levels of PCBs and trace metals in Crab Orchard Lake sediment, benthos, zooplankton and fish /

"HWRIC Project number HWR 87027."

Levels of living of U.S. farm families : selected annotated references, 1940-1955 /

Cover title.

Software Principles Yielding Better Levels of Consumer Knowledge Act : report of the Committee on Commerce, Science, and Transportation on S. 687.

"June 12, 2006."