http://europepmc.org/abstract/MED/25855536
http://europepmc.org/abstract/MED/8187092
http://europepmc.org/abstract/MED/22991414
http://europepmc.org/abstract/MED/18772397
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/8137263
http://europepmc.org/abstract/MED/7730141
http://europepmc.org/abstract/MED/22156295
http://europepmc.org/abstract/MED/25623214
http://europepmc.org/abstract/MED/23912084
http://europepmc.org/abstract/MED/25127237
http://europepmc.org/abstract/MED/8569192
http://europepmc.org/abstract/MED/9554525
http://europepmc.org/abstract/MED/27432539
http://europepmc.org/abstract/MED/23103869
http://europepmc.org/abstract/MED/28930868