Perhaps you should try some spelling variations:
"underground workings" » "underground works", "underground openings", "underground wireless"
"underground banking" » "underground tanks", "underground openings"
"underground parking" » "underground parts", "underground openings", "underground pipeline"

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: (((((("underground banking") OR ("underground parking"))) OR ("underground workings"))) OR ("underground mining")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"underground banking\") OR (\"underground parking\"))) or (\"underground workings\"))) or (\"underground mining\"))".
• Removing quotes may allow a broader search: (((((( underground banking ) OR ( underground parking ))) or ( underground workings ))) or ( underground mining )).
• Adding a wildcard symbol may retrieve word variants: (((((("underground banking") OR ("underground parking"))) or ("underground workings"))) or ("underground mining"))*.