http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/27135926
http://europepmc.org/abstract/MED/25961742
http://europepmc.org/abstract/MED/16959974
http://europepmc.org/abstract/MED/22116506
http://europepmc.org/abstract/MED/28921573