Perhaps you should try some spelling variations:
"12 national research center" » "12 operational research center" (Expand Search), "12 educational research center" (Expand Search), "12 translational research center" (Expand Search), "12 national research career" (Expand Search), "12 national research under" (Expand Search), "12 national research register" (Expand Search), "19 national research center" (Expand Search), "_ national research center" (Expand Search), "uk national research center" (Expand Search)
"a national research centre" » "a operational research centre" (Expand Search), "a educational research centre" (Expand Search), "a translational research centre" (Expand Search), "_ national research centre" (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"12 national research center\") OR (\"a national research centre\"))~".
• Removing quotes may allow a broader search: (( 12 national research center ) OR ( a national research centre ))~.
• Adding a wildcard symbol may retrieve word variants: (("12 national research center") OR ("a national research centre"))*.