http://europepmc.org/abstract/MED/29615459
http://europepmc.org/abstract/MED/9827724
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/28351340
http://europepmc.org/abstract/MED/8690521
http://europepmc.org/abstract/MED/27785980