Perhaps you should try some spelling variations:
"international political ecological services" » "international policy ecological services", "international political technological services", "international political ecologies services", "international political ecology services", "international political hydrological services", "international political clinical services", "international political meteorological services"
"International political economic studies" » "International political economy studies", "International policy economic studies", "International ecological economics studies", "International political economic status"

Try widening your search to All Fields.

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 studies") or ("international political ecological services"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("International political economic studies") OR ("international political ecological services")).
• Removing quotes may allow a broader search: (( International political economic studies ) or ( international political ecological services )).
• Adding a wildcard symbol may retrieve word variants: (("International political economic studies") or ("international political ecological services"))*.