Perhaps you should try some spelling variations:
2.30 communication » 2.3 communication, 2.7 communication, 1.3 communication
population area » population age, population africa, population share
technology u.s » technology uses, technology 2.2, technology use
u.s population » 2.1 population, 2.2 population, 2.3 population
4 development » 2 development, 4 developing
1 fabrique » la fabrique
area fig » area cir
fig 2.30 » fig 2.3, fig 2.35, fig 2.39
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 u.s population area fig 2.30 communication costs 4 development 1 fabrique.*.