Perhaps you should try some spelling variations:
formal transport » informal transport, rural transport, local transport
social transfer » social transfers
langues africa » language africa, wages africa, andes africa
costs chapter » cost chapter, courts chapter, posets chapter
transfer et » transfert et, transferts et, transfer der
vs formal » vs informal, its formal, _ formal
aguas vs » agens vs, aguas de, aguas do
et caso » el caso, del caso, en casos

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( aguas vs formal transport costs chapter ) OR ( langues africa social transfer et caso ))~.
• Adding a wildcard symbol may retrieve word variants: (( aguas vs formal transport costs chapter ) or ( langues africa social transfer et caso ))*.