Perhaps you should try some spelling variations:
communication cost » communication costs, communication costa, communications costs
de communication » mobile communication, online communication
cost hydropower » less hydropower, non hydropower, note hydropower
development age » development stage, development a, development aid
risk relations » risk regulations, milk relations, risk reductions
relations co » relations 3, relations 2, relations 5
age aortic » acute aortic, after aortic
co prices » do prices, co primes, coal prices
prices de » prices does, prices _, prices a

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

• Adding a wildcard symbol may retrieve word variants: technology risk relations co prices de communication cost hydropower development age aortic.*.