Perhaps you should try some spelling variations:
4.2 communication » 4.2 communications, 3.2 communication, 4.1 communication
developpement de » developpement des, developpement durable
risk population » risk populations, drive population, risk regulation
population wage » population age, population wide, population aged
4 developpement » de developpement, le developpement, et developpement
de afrique » de l'afrique, en afrique, l afrique
wage rate » wage rates
rate 4.2 » rates 4.2, rate 4.3, rate 5.2
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 risk population wage rate 4.2 communication costs 4 developpement de afrique.*.