Perhaps you should try some spelling variations:
research institutions » research institute
institutions series » institutions state, institutions africa, institutions social
et developpement » de developpement, le developpement, test development
variation using » variations during, variation und, variation among
developpement l » developpement il, developpement la, developpement de
typologie der » typologie des, ideologie der
der variation » de variation, does variation, die variation
series et » series e, series new, series ein
l afrique » en afrique

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

• Adding a wildcard symbol may retrieve word variants: typologie der variation using _ research institutions series et developpement l afrique.*.