Perhaps you should try some spelling variations:
communication costly » communication costs, communication costa, communications costs
oral communication » personal communication
trade developement » trade development, trade developments, trades development
developement en » developpement en, developpement et, developement _
ideologie de » ideologie der, ideologie des, ideologie du
de variation » der variation, die variation, does variation
costly trade » costs trade, country trade, costly than
2 oral » _ oral, 4 oral

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

• Adding a wildcard symbol may retrieve word variants: ideologie de variation _ 2 oral communication costly trade developement en afrique.*.