http://europepmc.org/abstract/MED/17013801
http://europepmc.org/abstract/MED/29420467
http://europepmc.org/abstract/MED/28945609
http://europepmc.org/abstract/MED/9921983
http://europepmc.org/abstract/MED/16161005
http://europepmc.org/abstract/MED/29876005
http://europepmc.org/abstract/MED/22653804
http://europepmc.org/abstract/MED/9635683
http://europepmc.org/abstract/MED/23104009
http://europepmc.org/abstract/MED/22923510
http://europepmc.org/abstract/MED/7743473
http://europepmc.org/abstract/MED/8372881