Perhaps you should try some spelling variations:
communications costs » communication costs, communications _
technologies based » technologies used, technology based, technologies a
based formulation » basic formulation, case formulation, based simulation
formulation needs » formulation des, information needs, formulation de
4 developpement » de developpement, le developpement, et developpement
developpement l » developpement il, developpement la, developpement de
needs using » needed using, needs doing, needs going
using data » missing data
l afrique » en afrique
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 based formulation needs using data communications costs 4 developpement l afrique.*.