Perhaps you should try some spelling variations:
opec communication » open communication, optic communication, ec communication
developpements en » developpement en, developpement et, developpements de
des variations » les variations, does variation, its variations
der opec » der oper, des opec, der opfer
a des » a der
a das » 1 das, 2 das, 3 das
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 variations _ der opec communication ((a des) OR (a das)) developpements en afrique.~".
• Adding a wildcard symbol may retrieve word variants: typologie des variations _ der opec communication ((a des) OR (a das)) developpements en afrique.*.