Perhaps you should try some spelling variations:
"support trade integrationstheorie 2." » "support der integrationstheorie 2.", "support eine integrationstheorie 2.", "support traditionelle integrationstheorie 2.", "support trade integrationstheorie fur.", "support trade integration theories.", "support trade interpretationstheorie 2.", "support trainer integrationstheorie 2.", "export trade integrationstheorie 2.", "import trade integrationstheorie 2."
"support grid irrigation scheme." » "support grid irrigation systems.", "support grain irrigation scheme.", "support drip irrigation scheme.", "support gray irrigation scheme.", "support agri irrigation scheme.", "support grant irrigation scheme.", "support group irrigation scheme."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("support trade integrationstheorie 2.") or ("support grid irrigation scheme."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("support trade integrationstheorie 2.") OR ("support grid irrigation scheme.")).
• Removing quotes may allow a broader search: (( support trade integrationstheorie 2. ) or ( support grid irrigation scheme. )).
• Adding a wildcard symbol may retrieve word variants: (("support trade integrationstheorie 2.") or ("support grid irrigation scheme."))*.