Perhaps you should try some spelling variations:
human transport » urban transport, rural transport, ocean transport
transport fuel » transport fares
transfer a » transfer _, transfer 4, transfer der
transfer 3 » transfer _, transfer 4, transfer 3.2
fuel gas » fuel tax
vague e » vague de, vague _, value e
e human » 2 human, 3 human, 1 human
guide a » guide _
a cast » a case, _ cast, a cash

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: (( vague e human transport fuel gas ) OR ( guide a cast ((transfer a) OR (transfer 3)) d ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( vague e human transport fuel gas ) or ( guide a cast ((transfer a) OR (transfer 3)) d ))~".
• Adding a wildcard symbol may retrieve word variants: (( vague e human transport fuel gas ) or ( guide a cast ((transfer a) OR (transfer 3)) d ))*.