http://europepmc.org/abstract/MED/27063598
http://europepmc.org/abstract/MED/27276561
http://europepmc.org/abstract/MED/20505189
http://europepmc.org/abstract/MED/22237025
http://europepmc.org/abstract/MED/22015770
http://europepmc.org/abstract/MED/25381062