Perhaps you should try some spelling variations:
4.2 communication » 4.2 communications, 3.2 communication, 4.1 communication
technology trade » technology trends, technology transfer, technology transfers
trade section » trade sector, trade action, trade sanctions
developing du » developing _, developing a, developing e
section wage » sector wage, section case, section based
4 developing » 3 developing
du afrique » en afrique, l afrique, de l'afrique
rates 4.2 » rates 4.5
costs 4 » costs _, costs a, costs 4.2

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

• Adding a wildcard symbol may retrieve word variants: technology trade section wage rates 4.2 communication costs 4 developing du afrique.*.