http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/25370038
http://europepmc.org/abstract/MED/9036877
http://europepmc.org/abstract/MED/21901162
http://europepmc.org/abstract/MED/12093899
http://europepmc.org/abstract/MED/25344691