Perhaps you should try some spelling variations:
voice communication » voice communications, mobile communication, device communication
developing country » developing countries
information case » information based, information can, information costs
technologien d » technologien ad, technologien _, technologien 1
3.5 developing » 3.3 developing, 3.2 developing, 1.5 developing
country access » counter access, countries access, country cross
d information » nd information, od information, und information
costs 3.5 » costs 4.2, costs 4.4, costs 2.3
case isc » case i, case ii, case iii

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

• Adding a wildcard symbol may retrieve word variants: technologien d information case isc voice communication costs 3.5 developing country access.*.