Perhaps you should try some spelling variations:
communication costa » communication costs, communications costs, communication cote
information centers » information contents, information officers
technologies 2.1 » technologies _, technologies 4, technologies a
el communication » cell communication, real communication, 3 communication
developing urban » development urban, developing human, developing areas
2.1 information » 3.1 information
3.3 developing » 4 developing, 2 developing, 1 developing
urban africa » urban area
centers 3.4 » centers 3.3, centers 3.8, centers 12.4
costa 3.3 » cost 3.2, costs 3.5, cost 2.3
3.4 el » 2.4 el, 3.4 eq, 3.4 et

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 centers 3.4 el communication costa 3.3 developing urban africa.*.