http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/28103826
http://europepmc.org/abstract/MED/27566247
http://europepmc.org/abstract/MED/29162652
http://europepmc.org/abstract/MED/21412130
http://europepmc.org/abstract/MED/22653804
http://europepmc.org/abstract/MED/28485815