Perhaps you should try some spelling variations:
oral communication » personal communication
der developpement » de developpement, des developpements, leur developpement
eines irrigation » minor irrigation, petite irrigation, saline irrigation
developpement en » developpement et, developpement des, developpement de
typologie eines » typologie cices, typologie einiger, typologie des
a der » _ der, 2 der, 3 der
6 hr » 6 hrm, 6 ihr, 6 mr
_ hr » _ r

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

• Performing a fuzzy search may retrieve terms with similar spellings: typologie eines irrigation ((6 hr) OR (_ hr)) oral communication a der developpement en afrique.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "typologie eines irrigation ((6 hr) OR (_ hr)) oral communication a der developpement en afrique.*".