Perhaps you should try some spelling variations:
"a development strategies." » "a development strategy."
"a development studies." » "a development series.", "a development services.", "a development strategy."
"clean development studies." » "clean development series.", "clean development services.", "clean development strategy.", "human development studies.", "urban development studies."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("a development studies.") OR ("clean development studies."))) or ("a development strategies."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("a development studies.") OR ("clean development studies."))) OR ("a development strategies.")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"a development studies.\") OR (\"clean development studies.\"))) or (\"a development strategies.\"))".
• Removing quotes may allow a broader search: (((( a development studies. ) OR ( clean development studies. ))) or ( a development strategies. )).
• Adding a wildcard symbol may retrieve word variants: (((("a development studies.") OR ("clean development studies."))) or ("a development strategies."))*.