http://europepmc.org/abstract/MED/24140581
http://europepmc.org/abstract/MED/23417712
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/28805995
http://europepmc.org/abstract/MED/24705251
http://europepmc.org/abstract/MED/23592488