http://europepmc.org/abstract/MED/7579458
http://europepmc.org/abstract/MED/8558920
http://europepmc.org/abstract/MED/8781433
http://europepmc.org/abstract/MED/8781434
http://europepmc.org/abstract/MED/11178628
http://europepmc.org/abstract/MED/7662979
http://europepmc.org/abstract/MED/8701987