Perhaps you should try some spelling variations:
"american and cooperative environmental policy" » "american and comparative environmental policy", "american and cooperative environment policy", "american and operative environmental policy"
"American and cooperative environments policy" » "American and competitive environments policy", "American and competitive environment policy", "American and pervasive environments policy", "American and cooperative environment policy", "American and cooperative environments privacy", "American and cooperative environments project"
"American and collaborative environments policy" » "American and collaborative environment policy", "American and collaborative environments privacy", "American and collaborative environments project", "American and collaboration environments policy"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("American and cooperative environments policy") OR ("American and collaborative environments policy"))) OR ("american and cooperative environmental policy")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"American and cooperative environments policy\") OR (\"American and collaborative environments policy\"))) or (\"american and cooperative environmental policy\"))".
• Removing quotes may allow a broader search: (((( American and cooperative environments policy ) OR ( American and collaborative environments policy ))) or ( american and cooperative environmental policy )).
• Adding a wildcard symbol may retrieve word variants: (((("American and cooperative environments policy") OR ("American and collaborative environments policy"))) or ("american and cooperative environmental policy"))*.