Perhaps you should try some spelling variations:
"mine development studies." » "mine development series.", "mine development services.", "mine development strategies.", "sme development studies.", "asian development studies.", "trade development studies."
"urban development africa." » "human development africa."
"a development strategy." » "_ development strategy.", "clean development strategy.", "asian development strategy."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("mine development studies.") or ("a development strategy."))) or ("urban development africa."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("mine development studies.") OR ("a development strategy."))) OR ("urban development africa.")).
• Removing quotes may allow a broader search: (((( mine development studies. ) or ( a development strategy. ))) or ( urban development africa. )).
• Adding a wildcard symbol may retrieve word variants: (((("mine development studies.") or ("a development strategy."))) or ("urban development africa."))*.