Perhaps you should try some spelling variations:
voice communication » voice communications, mobile communication, device communication
leur developpement » le developpement, deux developpements, de developpement
ideologie der » ideologie und, typologie der
der variation » de variation, does variation, die variation
variation des » variation _, variation 6, variation series
des afrique » en afrique, de l'afrique
des degats » des etats, des depots, des deas

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

• Adding a wildcard symbol may retrieve word variants: ideologie der variation des degats voice communication _ leur developpement des afrique.*.