Perhaps you should try some spelling variations:
"smart and sustainable public enrolment" » "smart and sustainable policy enrolment", "smart and sustainable built enrolment", "smart and sustainable policies enrolment", "smart and sustainable public involvement", "smart and sustainable public enforcement", "smart and sustainable public employment", "start and sustainable public enrolment"
"Smart and sustainable solid environment" » "Smart and sustainable society environment", "Smart and sustainable solutions environment", "Smart and sustainable policy environment", "Smart and sustainable world environment", "Smart and sustainable road environment"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("Smart and sustainable solid environment") or ("smart and sustainable public enrolment"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("Smart and sustainable solid environment") OR ("smart and sustainable public enrolment")).
• Removing quotes may allow a broader search: (( Smart and sustainable solid environment ) or ( smart and sustainable public enrolment )).
• Adding a wildcard symbol may retrieve word variants: (("Smart and sustainable solid environment") or ("smart and sustainable public enrolment"))*.