Perhaps you should try some spelling variations:
communication cost » communication costs, communication costa, communications costs
technologies 2.1 » technologies _, technologies 4, technologies a
de communication » mobile communication, online communication
2.1 information » 3.1 information
contents 4 » contents 1, contents _, contents i
cost 2 » cost 12, cost _, cost 4
4 de » 4 die, 4 der, 4 des

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

• Adding a wildcard symbol may retrieve word variants: technologies 2.1 information contents 4 de communication cost 2 development 1 africa.*.