Perhaps you should try some spelling variations:
technical experts » technical expertise
sustainable urban » sustainable use
urban development » human development
technical paper » technical report
central sea » central asia, central de, central asian
central s.a » central asia, central asian, central java

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

• Performing a fuzzy search may retrieve terms with similar spellings: world bank ((technical paper) OR (technical experts)). europe and ((central sea) or (central s.a)) environmental and socially sustainable urban development africa.~.
• If you are trying to use Boolean operators, they must be ALL CAPS: world bank ((technical paper) OR (technical experts)). europe AND ((central sea) OR (central s.a)) environmental AND socially sustainable urban development africa..
• The words AND, OR and NOT may confuse the search; try adding quotes: "world bank ((technical paper) OR (technical experts)). europe and ((central sea) or (central s.a)) environmental and socially sustainable urban development africa.".
• Adding a wildcard symbol may retrieve word variants: world bank ((technical paper) OR (technical experts)). europe and ((central sea) or (central s.a)) environmental and socially sustainable urban development africa.*.