Perhaps you should try some spelling variations:
"international political economy series" » "international policy economy series", "international political economic series"
"International social hydrological services" » "International social meteorological services", "International social ecological services"
international social » international journal, international seminar, international commercial

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 economy series") or ("International social hydrological services"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international political economy series") OR ("International social hydrological services"))*.
• Removing quotes may allow a broader search: (( international political economy series ) or ( International social hydrological services ))*.