Perhaps you should try some spelling variations:
"international agenda economic surveys" » "international trends economic surveys", "international agencies economic surveys", "international aid economic surveys", "international agenda economic studies", "international agenda economic systems", "international uganda economic surveys", "international algeria economic surveys", "international armenia economic surveys"
"national poppy economy series" » "national policy economy series", "national power economy series", "national port economy series", "national poppy economics series"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("national poppy economy series") OR ("international agenda economic surveys"))~.
• Removing quotes may allow a broader search: (( national poppy economy series ) or ( international agenda economic surveys ))~.
• Adding a wildcard symbol may retrieve word variants: (("national poppy economy series") or ("international agenda economic surveys"))*.