Perhaps you should try some spelling variations:
"female migration studies." » "female education studies.", "female migrants studies.", "fedie migration studies.", "feclimate migration studies.", "fechange migration studies."
"small migration studies." » "mail migration studies.", "skill migration studies.", "al migration studies."
"male migration studies." » "die migration studies.", "climate migration studies.", "change 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: (("small migration studies.") or ((("male migration studies.") OR ("female migration studies."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("small migration studies.") OR ((("male migration studies.") OR ("female migration studies.")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"small migration studies.\") or (((\"male migration studies.\") OR (\"female migration studies.\"))))".
• Removing quotes may allow a broader search: (( small migration studies. ) or ((( male migration studies. ) OR ( female migration studies. )))).
• Adding a wildcard symbol may retrieve word variants: (("small migration studies.") or ((("male migration studies.") OR ("female migration studies."))))*.