Perhaps you should try some spelling variations:
human transport » urban transport, rural transport, ocean transport
transport fuel » transport fares
gas transfer » cash transfer, mass transfer, a transfer
vague use » vague de
use human » use humans, e human, one human
fuel gas » fuel tax
guide a » guide _
a gas » _ gas, 2 gas, 3 gas
3 do » _ do, 1 do, 3 co

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: "(( vague use human transport fuel gas ) OR ( guide a gas transfer ((3 do) OR (3 d)) ))~".
• Adding a wildcard symbol may retrieve word variants: (( vague use human transport fuel gas ) OR ( guide a gas transfer ((3 do) OR (3 d)) ))*.