Perhaps you should try some spelling variations:
device communication » services communication, voice communication, mobile communication
developpement de » developpement des, developpement durable
des variation » does variation, de variation, der variation
bus device » bus service, vs device, bus services
a des » a der, a das
a de » a die, a der, _ de
typologie » typologies, typology

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 des variation _ bus device communication ((a de) OR (a des)) developpement de l'afrique.~".
• Adding a wildcard symbol may retrieve word variants: typologie des variation _ bus device communication ((a de) OR (a des)) developpement de l'afrique.*.