http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
National Pesticide Information Retrieval System (U.S.)
"The data for this directory is supplied ... by the National Pesticide Information Retrieval System (NPIRS) ... managed by Purdue University's Center for Environmental and Regulatory Information Systems (CERIS)"--P. 6.
Evans description based on: 5th edition (1997).
Federally registered pesticides. Distributor registrations