Perhaps you should try some spelling variations:
optic communication » optical communications, public communication, device communication
does developpement » de developpement, des developpements, does development
developpement l » developpement il, developpement la, developpement de
l afrique » en afrique
des dem » das dem, des der, des des
a does » 2 does, 4 does, 1 does

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

• If you are trying to use Boolean operators, they must be ALL CAPS: typology _ variation ((des dem) OR (die drei)) optic communication a does developpement l afrique.~.
• Adding a wildcard symbol may retrieve word variants: typology _ variation ((des dem) or (die drei)) optic communication a does developpement l afrique.*.