Perhaps you should try some spelling variations:
population rates » population debates, population related, population data
developpement il » developpement de, developpement et, developpement du
technology than » technology tax, technology trap, technology change
than population » change population, orphan population, urban population
4 developpement » de developpement, le developpement, et developpement
rates prices » water prices, gate prices, wages prices
il afrique » l afrique, en afrique
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 than population rates prices _ communication costs 4 developpement il afrique.*.