http://europepmc.org/abstract/MED/8103295
http://europepmc.org/abstract/MED/22855598
http://europepmc.org/abstract/MED/29386642
http://europepmc.org/abstract/MED/10084308
http://europepmc.org/abstract/MED/15990866
http://europepmc.org/abstract/MED/7756655