http://europepmc.org/abstract/MED/22634756
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/24931142
http://europepmc.org/abstract/MED/25724664
http://europepmc.org/abstract/MED/25021421
http://europepmc.org/abstract/MED/23788652