http://europepmc.org/abstract/MED/2183888
http://europepmc.org/abstract/MED/25595890
http://europepmc.org/abstract/MED/28157215
http://europepmc.org/abstract/MED/26341754
http://europepmc.org/abstract/MED/2659902
http://europepmc.org/abstract/MED/2660900
http://europepmc.org/abstract/MED/19458356
http://europepmc.org/abstract/MED/23603912
http://europepmc.org/abstract/MED/2668844
http://europepmc.org/abstract/MED/25903014
http://europepmc.org/abstract/MED/23377281
http://europepmc.org/abstract/MED/10673750
http://europepmc.org/abstract/MED/22675565
http://europepmc.org/abstract/MED/28671688
http://europepmc.org/abstract/MED/14982869
http://europepmc.org/abstract/MED/20806365
http://europepmc.org/abstract/MED/22237106
http://europepmc.org/abstract/MED/16533526
http://europepmc.org/abstract/MED/10071127
http://europepmc.org/abstract/MED/24166518