Perhaps you should try some spelling variations:
"import data integrationstheorie 2." » "import der integrationstheorie 2.", "import eine integrationstheorie 2.", "import aa migrationstheorie 2.", "import data integrationstheorie fur.", "import data integration theories.", "import data interpretationstheorie 2.", "import duty integrationstheorie 2."
"support grain irrigation schemes." » "support grain irrigation scheme.", "support grain irrigation systems.", "support gray irrigation schemes.", "support gravity irrigation schemes.", "support drip irrigation schemes.", "support grant irrigation schemes.", "support grid irrigation schemes.", "support trainer irrigation schemes."

Try widening your search to All Fields.

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

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