Perhaps you should try some spelling variations:
"world manko working paper" » "world django working paper", "world manner working paper", "world manual working paper", "world many working paper", "world make working paper", "world mark working paper", "world manko working papers"
"world macro working paper" » "world macros working paper", "world across working paper", "world macro blocking paper", "word macro working paper", "world mark working paper", "world mario working paper", "world mapro working paper", "world mayro working paper", "world maxro working paper", "world macro working papers"
"world mac working paper" » "world c working paper", "world cc working paper", "world macros working paper", "world map working paper", "world may working paper", "world max working paper", "world mac working papers"

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