Perhaps you should try some spelling variations:
2.3 communication » 3.2 communication, de communication, 4 communication
developpement en » developpement et, developpement des, developpement de
technology low » technology flow, technology law, technology led
elevation data » election data, generation data, excavation data
low elevation » _ elevation, st elevation
data rate » data rates, data data, data related
rate 2.3 » rates 2.3, rate 2.4, rate 4.3

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

• Adding a wildcard symbol may retrieve word variants: technology low elevation data rate 2.3 communication costs _ developpement en afrique.*.