Perhaps you should try some spelling variations:
gabon communications » gambia communications, faso communications, japan communications
developpement de » developpement des, developpement durable
typologie de » typologie des, typologie der, typologien der
de variation » der variation, die variation, does variation
a set » _ set
a et » a net, a bet, a jet

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

• Performing a fuzzy search may retrieve terms with similar spellings: typologie de variation _ does gabon communications ((a et) OR (a set)) developpement de l'afrique.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "typologie de variation _ does gabon communications ((a et) OR (a set)) developpement de l'afrique.*".