Perhaps you should try some spelling variations:
oral communication » personal communication
communication crop » communication cross, communication europe, communication across
trade development » software development
development des » development does, development desd, development ds
des variation » does variation, de variation, der variation
des afrique » en afrique, de l'afrique
crop trade » crops trade, crop storage
4 sex » _ sex, a sex
4 ex » 14 ex, 4 exh, _ ex
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 ((4 ex) OR (4 sex)) oral communication crop trade development des afrique.~".
• Adding a wildcard symbol may retrieve word variants: typologie des variation ((4 ex) OR (4 sex)) oral communication crop trade development des afrique.*.