Perhaps you should try some spelling variations:
voice communication » voice communications, mobile communication, device communication
developpement en » developpement et, developpement des, developpement de
typologie der » typologie des, ideologie der
der variation » de variation, does variation, die variation
variation des » variation _, variation 6, variation series
new voice » new voices, one voice
3 das » 1 das
2 das » 1 das

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "typologie der variation des new voice communication ((3 das) OR (2 das)) developpement en afrique.~".
• Adding a wildcard symbol may retrieve word variants: typologie der variation des new voice communication ((3 das) OR (2 das)) developpement en afrique.*.