Perhaps you should try some spelling variations:
"support migrant integration theories." » "support migrant integration theorems.", "support migrant integrationstheorie 2.", "support migrant integration theory.", "support market integration theories.", "support migrants integration theories.", "support grant integration theories.", "supporting migrants integration theories."
"support price indexation series." » "support price interaction series.", "support price integration series.", "support price innovation series.", "support price inflation series.", "support price information series.", "support process indexation series.", "support policy indexation series.", "export price indexation series."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("support price indexation series.") or ("support migrant integration theories."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("support price indexation series.") OR ("support migrant integration theories.")).
• Removing quotes may allow a broader search: (( support price indexation series. ) or ( support migrant integration theories. )).
• Adding a wildcard symbol may retrieve word variants: (("support price indexation series.") or ("support migrant integration theories."))*.