Perhaps you should try some spelling variations:
technology change » technological change, technological changes
change population » chinese population, age population, large population
population values » population issues, population changes, population age
1.1 communication » 4.1 communication, 1.3 communication, 1.4 communication
developpement en » developpement et, developpement des, developpement de
values past » values part, values asv, values case
past 1.1 » past 11.1, cast 1.1, past 1.1.2

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

• Adding a wildcard symbol may retrieve word variants: technology change population values past 1.1 communication costs _ developpement en afrique.*.