http://europepmc.org/abstract/MED/25957691
http://europepmc.org/abstract/MED/29844865
http://europepmc.org/abstract/MED/19117336
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/25029120
http://europepmc.org/abstract/MED/25496513
http://europepmc.org/abstract/MED/26968814
http://europepmc.org/abstract/MED/25344691
http://europepmc.org/abstract/MED/27756406