Perhaps you should try some spelling variations:
international efforts » international airports, international energy, international airport
interaction series » interactions series, interaction studies, interaction terms
cost international » costs international, costea international, 1st international
fare interaction » face interaction, face interactions, fare integration
supply fare » supply farm, supply case, supply figure
supply cost » supply costs

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply fare interaction series. ) OR ( supply cost international efforts. ))~.
• Adding a wildcard symbol may retrieve word variants: (( supply fare interaction series. ) or ( supply cost international efforts. ))*.