Perhaps you should try some spelling variations:
technology create » technology creates, technology rate, technologies create
create population » area population, oleae population, peace population
3.2 communication » 3 communication, 2.3 communication, de communication
population per » population panel, population p230, population area
des afrique » en afrique, de l'afrique
per fig » per firm
fig 3.2 » fig 5.2, fig 2.2, fig 3.1

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

• Adding a wildcard symbol may retrieve word variants: technology create population per fig 3.2 communication costs _ developpement des afrique.*.