usasearch.gov may help find hearings, position papers, proposals, etc., put out by both federal and state agencies regarding standards or requirements for "clean" or "green" industries and jobs. The search: "clean industry" standards gets 75 hits; "clean jobs" definition gets 30; "defining green jobs" gets 20. Compare Google search using site limiters: "defining green jobs" site:gov gets 15 unique sites; "defining green jobs" site:edu gets 17; "defining green" site:edu gets 181; but "clean industry standards" site:edu gets only 1.

Since such definitions will require political compromise, consensus, and ultimately people's votes (or at least their representatives' votes or executive orders), the free government sites may be as valid a search as you are likely to get. But the major search engines are by no means complete searches. It is wise to go into more specific sites, for example California.gov, which gets 92 unique hits for the search: "definition of green". Note that phrases including the traditional "stop" words such as a, an, of, the, in, etc. are still a bit dicey. Some newer search engines will find sites that have exact phrases including these words; others will simply go into "smart search" mode and look only for the "significant" words - possibly giving higher relevance to the sites that have those main words closer together.

There are some major free Federal databases, such as the Department of Energy's OSTI and DTIC, that have very many full text reports. For a start, you may prefer to get many at a time in Science.gov, especially since a major player, EPA, is not known for having an easy to search database. Its Technical Reports and Publications doesn't give any quick hints which database to start with, or how to search.

If you want to bolster your White Paper with scholarly articles, many of the commercial full text databases might be worth searching for theoretical work on these definitions. Most of them offer "proximity search", that allows you to specify that words must be no more than a set number of words apart. For example, JSTOR gets 3 hits for the search: "standards clean occupations"~20. But you can also try exact phrase: "defining green" gets 10 articles. Things such as "Green's Functions" will muddy the water. Try: "definition green"~2 AND environment* (29 hits in JSTOR).

Proximity search is different in the various commercial databases. ScienceDirect, a VERY scholarly and technical (and LARGE) collection of journals published by Elsevier, gets 103 articles for: clean w/5 industr* w/5 standards. Probably easier to find at more academic and maybe even a few public libraries is Academic Search, sometimes listed under Ebsco databases. Academic Search Premier gets 22 articles for: clean w5 industr* w5 standards. Business Source Complete (also Ebsco) surprisingly gets only 11 for the same search. Note that Ebsco leaves out the / in the "W" operator.

There are many other databases that might help with this project, but these 3 big full-text ones may be your best start - after exhausting the Federal and state sites.