"efficient" - key terms from Wikipedia

clock cycle efficient
efficient
efficient algorithm
efficient and prompt handling
efficient cause
efficient energy use
efficient filtration
efficient frontier
efficient market
efficient market hypothesis
efficient than
energy efficient
energy efficient northbridge design
fuel efficient
less efficient
more efficient
more efficient than class
more energy efficient
more fuel efficient vehicles
most efficient
most efficient process
most efficient shape
most fuel efficient
pareto efficient
space efficient
systems are more efficient when
very efficient