Perhaps you should try some spelling variations:
frontiers collection » containers collection, frontiers section, folders collection
frontiers selection » frontiers section, frontier section, frontier electron
models connections » model connections, models connection, model connection

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: %22the ((((frontiers collection) OR (models connections))) OR (frontiers selection))%22.
• Adding a wildcard symbol may retrieve word variants: %22the ((((frontiers collection) or (models connections))) or (frontiers selection))%22*.