http://europepmc.org/abstract/MED/28377483
http://europepmc.org/abstract/MED/27834349
http://europepmc.org/abstract/MED/17539962
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/10802655
http://europepmc.org/abstract/MED/8617483
http://europepmc.org/abstract/MED/17300232
http://europepmc.org/abstract/MED/25072932