http://europepmc.org/abstract/MED/25957691
http://europepmc.org/abstract/MED/29844865
http://europepmc.org/abstract/MED/24755471
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/22009941
http://europepmc.org/abstract/MED/24382590
http://europepmc.org/abstract/MED/25344691
http://europepmc.org/abstract/MED/26109429