Perhaps you should try some spelling variations:
barriers formulation » basic formulation, barriers irradiation, barriers location
chile communications » china communications, machine communications, mobile communications
communications costs » communication costs, communications _
technology barriers » technologies barriers, technological barriers, methodology barriers
formulation 3 » formulation _, formulations _, formulating _
development 4 » development 1
use chile » use china, de chile, use agile
costs a » costs _, costs 4
4 areas » 1 areas, 2 areas, 4 areal
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: technology barriers formulation 3 use chile communications costs a development 4 areas.*.