Perhaps you should try some spelling variations:
conversion factor » conversion factors, conversion rate
developpement de » developpement des, developpement durable
debt conversion » data conversion, forest conversion
a developpement » au developpement, de developpement, le developpement
technologies 2 » technologies _, technologies 4
de afrique » de l'afrique, en afrique, l afrique
factor a » factor _, factor 1, factor 2
2 yes » v2 yes, 2 les, 2 des
_ yes » _ yet

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "technologies 2 information ((2 yes) OR (_ yes)) debt conversion factor a developpement de afrique.~".
• Adding a wildcard symbol may retrieve word variants: technologies 2 information ((2 yes) OR (_ yes)) debt conversion factor a developpement de afrique.*.