Use the same search strategies:
quotes around phrases
* for truncation
and / or
In addition, since you are searching the fulltext, you might need to bring the words closer together:
/s = same sentence
"food security" /s refugee*
/p = same paragraph
"food security" /p refugee* /p maryland
Example search: Recycling at UMD
Notice in results - limit by publication type, timeline, sources
