http://europepmc.org/abstract/MED/11244334
http://europepmc.org/abstract/MED/8272291
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/27566247
http://europepmc.org/abstract/MED/25233892
http://europepmc.org/abstract/MED/25962155
http://europepmc.org/abstract/MED/21168197