Perhaps you should try some spelling variations:
"world bank regional and sectional studies" » "world bank regional and functional studies", "world bank regional and regional studies", "world bank regional and sectional study", "world lanka regional and sectional studies", "world mask regional and sectional studies", "world park regional and sectional studies"
"world bank regional and sectoral studies" » "world bank regional and sector studies", "world bank regional and doctoral studies", "world bank regional and temporal studies", "world lanka regional and sectoral studies", "world mask regional and sectoral studies", "world park regional and sectoral studies"
"world bank regional and spectral studies" » "world bank regional and structural studies", "world lanka regional and spectral studies", "world mask regional and spectral studies", "world park regional and spectral studies"

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 bank regional and sectoral studies") OR ((("world bank regional and spectral studies") OR ((("World Bank regional and general studies") OR ("World Bank regional and genetic studies"))))))) OR ("world bank regional and sectional studies")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"world bank regional and sectoral studies\") or (((\"world bank regional and spectral studies\") or (((\"World Bank regional and general studies\") OR (\"World Bank regional and genetic studies\"))))))) or (\"world bank regional and sectional studies\"))".
• Removing quotes may allow a broader search: (((( world bank regional and sectoral studies ) or ((( world bank regional and spectral studies ) or ((( World Bank regional and general studies ) OR ( World Bank regional and genetic studies ))))))) or ( world bank regional and sectional studies )).
• Adding a wildcard symbol may retrieve word variants: (((("world bank regional and sectoral studies") or ((("world bank regional and spectral studies") or ((("World Bank regional and general studies") OR ("World Bank regional and genetic studies"))))))) or ("world bank regional and sectional studies"))*.