Perhaps you should try some spelling variations:
"world bank working OR band working paper" » "world black working OR band working paper", "world manko working OR band working paper", "world pack working OR band working paper", "world bank working OR bandes working paper", "world bank working OR board working paper", "world bank working OR based working paper"
"world bank working OR band working papers" » "world black working OR band working papers", "world manko working OR band working papers", "world pack working OR band working papers", "world bank working OR bandes working papers", "world bank working OR board working papers", "world bank working OR based working papers"

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

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