Perhaps you should try some spelling variations:
development second » development beyond, development section, development sectors
de communication » mobile communication, online communication
interaction pet » interaction pt, interaction ports, interaction term
4 development » 2 development, 4 developing
pet data » det data, set data, debt data
data de » data den, data die, data do
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: technologies _ interaction pet data de communication costs 4 development second afrique.*.