Perhaps you should try some spelling variations:
"international ports economy series" » "international airports economy series", "international poverty economy series", "international efforts economy series", "international ports economics series", "international porn economy series", "international sports economic series", "international export economy series"
"national policy autonomy series" » "national poverty autonomy series", "national political autonomy series", "national policy astronomy series", "national policy autonomy states", "national policy autonomy survey"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("national policy autonomy series") OR ("international ports economy series"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"national policy autonomy series\") OR (\"international ports economy series\"))".
• Removing quotes may allow a broader search: (( national policy autonomy series ) OR ( international ports economy series )).
• Adding a wildcard symbol may retrieve word variants: (("national policy autonomy series") OR ("international ports economy series"))*.