Perhaps you should try some spelling variations:
"supply chain integrationstheorie 2." » "supply eine integrationstheorie 2.", "supply der integrationstheorie 2.", "supply chain integrationstheorie fur.", "supply chain integration theories.", "supply chain interpretationstheorie 2."
"supply grid irrigation schemes." » "supply grid irrigation scheme.", "supply grid irrigation systems.", "supply grain irrigation schemes.", "supply drip irrigation schemes.", "supply gray irrigation schemes.", "supply crowd irrigation schemes.", "supply great irrigation schemes.", "support grid irrigation schemes."

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

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