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

Try widening your search to All Fields.

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 series.") or ("clean development studies."))) or ("a development process."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("a development series.") OR ("clean development studies."))) OR ("a development process.")).
• Removing quotes may allow a broader search: (((( a development series. ) or ( clean development studies. ))) or ( a development process. )).
• Adding a wildcard symbol may retrieve word variants: (((("a development series.") or ("clean development studies."))) or ("a development process."))*.