http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/29420467
http://europepmc.org/abstract/MED/27034166
http://europepmc.org/abstract/MED/24201163
http://europepmc.org/abstract/MED/26249178
http://europepmc.org/abstract/MED/23563269