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

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 public environment") or ("Smart and sustainable solid enrolment"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("smart and sustainable public environment") OR ("Smart and sustainable solid enrolment"))*.
• Removing quotes may allow a broader search: (( smart and sustainable public environment ) or ( Smart and sustainable solid enrolment ))*.