Perhaps you should try some spelling variations:
opec communication » open communication, optic communication, ec communication
des developpement » des developpements, de developpement, le developpement
developpement il » developpement de, developpement et, developpement du
variation des » variation _, variation 6, variation series
il afrique » l afrique, en afrique
dr opec » der opec, der oper, des opec
a des » a der, a das

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

• Adding a wildcard symbol may retrieve word variants: typology _ variation des dr opec communication a des developpement il afrique.*.