Perhaps you should try some spelling variations:
oral communication » personal communication
developpement de » developpement des, developpement durable
typologie der » typologie des, ideologie der
der variation » de variation, does variation, die variation
variation den » variation des, variation der, variation de
de afrique » de l'afrique, en afrique, l afrique
den ddr » der ddr, dem ddr, des ddr
a bet » a best, a bent, a beta
a et » a set, a net, a jet

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: typologie der variation den ddr oral communication ((a et) OR (a bet)) developpement de afrique.~.
• Adding a wildcard symbol may retrieve word variants: typologie der variation den ddr oral communication ((a et) or (a bet)) developpement de afrique.*.