Perhaps you should try some spelling variations:
"world banks technical paper" » "world tasks technical paper", "world basics technical paper", "world apps technical paper", "world bank's technical paper", "work banks technical paper", "world back technical paper"
"world bank technical paper" » "world lanka technical paper", "world bands technical paper", "world pack technical paper"
"world apis technical paper" » "world api technical paper", "world apps technical paper", "world basics technical paper", "world anis technical paper", "world kpis technical paper"
"world apis technical papers" » "world api technical papers", "world apps technical papers", "world basics technical papers", "world anis technical papers", "world kpis technical papers"

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