Perhaps you should try some spelling variations:
oral communication » personal communication
gas developpement » gas development, au developpement, des developpements
developpement en » developpement et, developpement des, developpement de
variation des » variation _, variation 6, variation series
typologie et » typologie des, typologie der, typologie von
et variation » der variation, bei variation, 2 variation
des water » does water, des warner, less water

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

• Adding a wildcard symbol may retrieve word variants: typologie et variation des water oral communication _ gas developpement en afrique.*.