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

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