http://europepmc.org/abstract/MED/15684603
http://europepmc.org/abstract/MED/23377281
http://europepmc.org/abstract/MED/22675565
http://europepmc.org/abstract/MED/28671688
http://europepmc.org/abstract/MED/8180387
http://europepmc.org/abstract/MED/10071127
http://europepmc.org/abstract/MED/28157215