http://europepmc.org/abstract/MED/29844865
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/28978093
http://europepmc.org/abstract/MED/25617745
http://europepmc.org/abstract/MED/25344691
http://europepmc.org/abstract/MED/27756406