http://europepmc.org/abstract/MED/29681454
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/18948947
http://europepmc.org/abstract/MED/25112956
http://europepmc.org/abstract/MED/27923066
http://europepmc.org/abstract/MED/22980975