Perhaps you should try some spelling variations:
personal communication » interpersonal communication
variation series » education series, action series, edition series
de developpement » sme development
developpement en » developpement et, developpement des, developpement de
typologie price » typologie cices
price variation » price variations
dem personal » der personal, de personal, des personal
series dem » series de, series nejm, series d
a de » a die, a der, a des

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

• Adding a wildcard symbol may retrieve word variants: typologie price variation series dem personal communication a de developpement en afrique.*.