http://europepmc.org/abstract/MED/28302137
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/9354678
http://europepmc.org/abstract/MED/24388756
http://europepmc.org/abstract/MED/15337798
http://europepmc.org/abstract/MED/29386642
http://europepmc.org/abstract/MED/17881637