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"
"international energy economics services" » "international energy economics series", "international energy economics soviet", "international energy economics ethics"

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