Perhaps you should try some spelling variations:
electronic resources » electronic resource, electronic devices
electric resource » electronic resource, electric source, electricity resource
3a apache » 33 apache, 3.2 apache, 3.6 apache
a apache » _ apache, 1 apache, 4 apache
3 apache » _ apache, 1 apache, 4 apache

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: %22spark %((electric resource) OR (electronic resources)) %((((3a apache) OR (a apache))) OR (3 apache)) software foundation%29%22.
• Adding a wildcard symbol may retrieve word variants: %22spark %((electric resource) or (electronic resources)) %((((3a apache) or (a apache))) or (3 apache)) software foundation%29%22*.