In this way, they are a very useful complement to cancer therapy. (cancertutor.com)
Sales and Marketing the Six Sigma Way is interested in sales in a far more macro fashion than SPIN selling and as such is a useful complement. (tonyhaile.com)
A cheap and biodegradable material made from wood pulp can turn footsteps into electricity — a useful complement to renewables like solar (newscientist.com)