Perhaps you should try some spelling variations:
"international species ecological services" » "international series ecological services", "international agencies ecological services", "international studies ecological services", "international species hydrological services", "international species clinical services", "international species meteorological services", "international social ecological services", "international socio ecological services", "international cities ecological services"
"international prices economic services" » "international prices economics series", "international prices economic studies", "international prices economic surveys", "international crises economic services", "international prices econometric services", "international services economic services"

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