Perhaps you should try some spelling variations:
"trade development studies." » "trade development series.", "trade development services.", "trade development strategies.", "software development studies."
"a development studies." » "a development series.", "a development services.", "a development strategies."
"mine development process." » "mine development projects.", "mine development programs.", "mine development policies.", "sme development process.", "business development process."

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