http://europepmc.org/abstract/MED/24951608
http://europepmc.org/abstract/MED/24369359
http://europepmc.org/abstract/MED/25274248
http://europepmc.org/abstract/MED/27154293
http://europepmc.org/abstract/MED/23199549
http://europepmc.org/abstract/MED/26475379
http://europepmc.org/abstract/MED/27502722
http://europepmc.org/abstract/MED/24944587