Perhaps you should try some spelling variations:
voice communication » voice communications, mobile communication, device communication
developpement l » developpement il, developpement la, developpement de
der variation » de variation, does variation, die variation
typology der » typologie der, typologien der, typologie des
der voice » user voice, new voice
l afrique » en afrique
3 auf » i auf, a auf, b auf
3 au » 3 a, 3 zu, 3 eu

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: "typology der variation _ der voice communication ((3 au) OR (3 auf)) developpement l afrique.~".
• Adding a wildcard symbol may retrieve word variants: typology der variation _ der voice communication ((3 au) OR (3 auf)) developpement l afrique.*.