Perhaps you should try some spelling variations:
"international political economic series" » "international policy economic series", "international political economy series", "international ecological economics series", "international political economic services", "international political economic theories", "international political economic surveys"
"national poverty economic studies" » "national policy economic studies", "national energy economic studies", "national poverty economic status", "national poverty economic surveys"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("international political economic series") OR ("national poverty economic studies"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"international political economic series\") OR (\"national poverty economic studies\"))".
• Removing quotes may allow a broader search: (( international political economic series ) OR ( national poverty economic studies )).
• Adding a wildcard symbol may retrieve word variants: (("international political economic series") OR ("national poverty economic studies"))*.