Perhaps you should try some spelling variations:
"international rican economy series" » "international african economy series", "international rice economy series", "international american economy series", "international rican economics series", "international roman economy series", "international rich economy series"
"international energy economic theories" » "international energy economic theory", "international energy economics series", "international energy economics theories", "international energy economy theories", "international ecology economic theories"

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