Perhaps you should try some spelling variations:
technological barriers » technical barriers, psychological barriers, technological factors
barriers formulation » basic formulation, barriers irradiation, barriers location
chile communications » china communications, machine communications, mobile communications
communications costs » communication costs, communications _
formulation 3 » formulation _, formulations _, formulating _
use chile » use china, de chile, use agile
1 areas » 1 area, 2 areas, 4 areas
3 use » _ use, 2 use, 4 use

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

• Adding a wildcard symbol may retrieve word variants: technological barriers formulation 3 use chile communications costs _ development 1 areas.*.