Perhaps you should try some spelling variations:
1973 communication » 13 communication, 1.3 communication, 19 communication
technology change » technological change, technological changes
change population » chinese population, age population, large population
population rates » population debates, population related, population data
de developpement » sme development
developpement en » developpement et, developpement des, developpement de
rates dan » rates data, rates hans, rates a
dan 1973 » van 1973, dan 1963, can 1973
costs de » costs _, costs 4, costs a

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

• Adding a wildcard symbol may retrieve word variants: technology change population rates dan 1973 communication costs de developpement en afrique.*.