http://europepmc.org/abstract/MED/22962301
http://europepmc.org/abstract/MED/26269449
http://europepmc.org/abstract/MED/25545346
http://europepmc.org/abstract/MED/26700204
http://europepmc.org/abstract/MED/23010473
http://europepmc.org/abstract/MED/25720320