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http://europepmc.org/abstract/MED/29420467
http://europepmc.org/abstract/MED/11172591
http://europepmc.org/abstract/MED/23700467
http://europepmc.org/abstract/MED/23139211
http://europepmc.org/abstract/MED/16828225
http://europepmc.org/abstract/MED/21892161