http://europepmc.org/abstract/MED/29844865
http://europepmc.org/abstract/MED/19503063
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/20565851
http://europepmc.org/abstract/MED/25194673
http://europepmc.org/abstract/MED/20979647
http://europepmc.org/abstract/MED/25344691
http://europepmc.org/abstract/MED/26109429
http://europepmc.org/abstract/MED/11508658