Perhaps you should try some spelling variations:
"national research association" » "national research dissemination", "national research information", "national research education", "educational research association", "translational research association", "international research association"
"operational research association" » "operational research dissemination", "operational research information", "operational research education", "operations research association", "international research association", "educational research association"

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: "((\"national research association\") OR (\"operational research association\"))".
• Removing quotes may allow a broader search: (( national research association ) OR ( operational research association )).
• Adding a wildcard symbol may retrieve word variants: (("national research association") OR ("operational research association"))*.