Perhaps you should try some spelling variations:
crisis communication » risk communication, mass communication
separation using » operation using, separation among, separation und
du developpement » de developpement, le developpement, et developpement
developpement en » developpement et, developpement des, developpement de
air separation » a separation, after separation, first separation
typologie air » typologie wird, typologie der, typologie am
les crisis » las crisis, les crises, its crisis
using les » using less, using aes, using files
a du » a d, a de, a u

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

• Adding a wildcard symbol may retrieve word variants: typologie air separation using les crisis communication a du developpement en afrique.*.