http://europepmc.org/abstract/MED/12474227
http://europepmc.org/abstract/MED/29615459
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/28062544
http://europepmc.org/abstract/MED/19534622
http://europepmc.org/abstract/MED/27713418