Perhaps you should try some spelling variations:
"scale immigration rules." » "scale irrigation rules.", "race immigration rules.", "skilled immigration rules.", "scale immigration quotas.", "scale migration rates.", "scale immigration law."
"scale migration studies." » "female migration studies.", "can migration studies.", "trade migration studies."
"male migration studies." » "female migration studies.", "mass migration studies.", "a migration studies."

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: (((("scale immigration rules.") or ("male migration studies."))) or ("scale migration studies."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("scale immigration rules.") OR ("male migration studies."))) OR ("scale migration studies.")).
• Removing quotes may allow a broader search: (((( scale immigration rules. ) or ( male migration studies. ))) or ( scale migration studies. )).
• Adding a wildcard symbol may retrieve word variants: (((("scale immigration rules.") or ("male migration studies."))) or ("scale migration studies."))*.