Perhaps you should try some spelling variations:
"world brand working paper" » "world branch working paper", "world board working paper", "world beyond working paper", "word brand working paper", "world bank working paper"
"world band working paper" » "world bandes working paper", "world board working paper", "world based working paper", "world bank working paper", "world bond working paper", "world hand working paper"
"world band working papers" » "world bandes working papers", "world board working papers", "world based working papers", "world bank working papers", "world bond working papers", "world hand 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 band working paper\") OR (\"world band working papers\"))) OR (\"world brand working paper\"))".
• Removing quotes may allow a broader search: (((( world band working paper ) OR ( world band working papers ))) OR ( world brand working paper )).
• Adding a wildcard symbol may retrieve word variants: (((("world band working paper") OR ("world band working papers"))) OR ("world brand working paper"))*.