Perhaps you should try some spelling variations:
"national forestry economic status" » "national forest economic status", "international forestry economic status", "national forest economics status", "national country economic status", "national foreign economic status", "national forestry economic sectors", "national forestry socioeconomic status"
"international prices economic theories" » "international prices economic theory", "international prices economics series", "international crises economic theories", "international prices econometric theories", "international services economic theories"

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