Perhaps you should try some spelling variations:
"world macros working paper" » "world ratios working paper", "world mac working paper", "world machines working paper", "word macros working paper", "world across working paper", "world microbes working paper", "world macs working paper", "world marios working paper"
"world macro working paper" » "world mac working paper", "world avro working paper", "world manko working paper", "word macro working paper", "world mario working paper"
"world mark working papers" » "world dark working papers", "world market working papers", "world markup working papers", "world map working papers", "world may 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 mark working papers\") OR (((\"world macro working paper\") OR (\"world macros working paper\"))))".
• Removing quotes may allow a broader search: (( world mark working papers ) OR ((( world macro working paper ) OR ( world macros working paper )))).
• Adding a wildcard symbol may retrieve word variants: (("world mark working papers") OR ((("world macro working paper") OR ("world macros working paper"))))*.