http://europepmc.org/abstract/MED/26503331
http://europepmc.org/abstract/MED/9120722
http://europepmc.org/abstract/MED/8060323
http://europepmc.org/abstract/MED/9624535
http://europepmc.org/abstract/MED/20668451
http://europepmc.org/abstract/MED/7563154
http://europepmc.org/abstract/MED/8631583
http://europepmc.org/abstract/MED/9484839
http://europepmc.org/abstract/MED/10557071
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/8521414
http://europepmc.org/abstract/MED/7591275
http://europepmc.org/abstract/MED/11820618
http://europepmc.org/abstract/MED/23355336
http://europepmc.org/abstract/MED/9816274
http://europepmc.org/abstract/MED/22696596