Perhaps you should try some spelling variations:
communication cost » communication costs, communication costa, communications costs
technologien aids » technologien als, technologien ad, technologien des
aids information » chandos information, series information
de communication » mobile communication, online communication
3.3 developing » 4 developing, 2 developing, 1 developing
4.2 debt » 4.2 der, 4.2 deep, 2.5 debt
cost 3.3 » cost 3.2, cost 2.3, cost 3.4
debt de » debt do, debt debt, debt gdp

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

• Adding a wildcard symbol may retrieve word variants: technologien aids information 4.2 debt de communication cost 3.3 developing _ areas.*.