Perhaps you should try some spelling variations:
"work blacks technical paper" » "work blocks technical paper", "work places technical paper", "work stacks technical paper", "work blacks technical papers", "work black technical paper", "work back technical paper", "work block technical paper"
"world bank technical paper" » "world bank technical papers", "world bands technical paper", "world pack technical paper", "world rack technical paper"
"world lanka technical paper" » "world lanka technical papers", "world land technical paper", "world albania technical paper", "world uganda technical paper", "world banks technical paper", "world lack technical paper", "world lake technical paper"
"work banks technical paper" » "work banks technical papers", "work tasks technical paper", "work basics technical paper", "work apis technical paper", "work bank technical paper", "world banks technical paper", "work back technical paper"

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: (((("world bank technical paper") OR ("world lanka technical paper"))) OR ((("work banks technical paper") OR ("work blacks technical paper")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"world bank technical paper\") OR (\"world lanka technical paper\"))) or (((\"work banks technical paper\") or (\"work blacks technical paper\"))))".
• Removing quotes may allow a broader search: (((( world bank technical paper ) OR ( world lanka technical paper ))) or ((( work banks technical paper ) or ( work blacks technical paper )))).
• Adding a wildcard symbol may retrieve word variants: (((("world bank technical paper") OR ("world lanka technical paper"))) or ((("work banks technical paper") or ("work blacks technical paper"))))*.