Perhaps you should try some spelling variations:
"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", "start and sustainable solid environment"
"smart and sustainable city environment" » "smart and sustainable cities environment", "smart and sustainable _ environment", "smart and sustainable mobility environment", "smart and sustainable society environment", "smart and sustainable data environment", "smart and sustainable policy environment", "start and sustainable city 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 city environment") or ("smart and sustainable solid environment"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("smart and sustainable city environment") OR ("smart and sustainable solid environment")).
• Removing quotes may allow a broader search: (( smart and sustainable city environment ) or ( smart and sustainable solid environment )).
• Adding a wildcard symbol may retrieve word variants: (("smart and sustainable city environment") or ("smart and sustainable solid environment"))*.