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

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 services") OR ("national poverty economic surveys"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"international political economic services\") OR (\"national poverty economic surveys\"))*".
• Removing quotes may allow a broader search: (( international political economic services ) OR ( national poverty economic surveys ))*.