http://europepmc.org/abstract/MED/8653691
http://europepmc.org/abstract/MED/11040453
http://europepmc.org/abstract/MED/11787853
http://europepmc.org/abstract/MED/25855536
http://europepmc.org/abstract/MED/18772397
http://europepmc.org/abstract/MED/22762308
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/22156295
http://europepmc.org/abstract/MED/25623214
http://europepmc.org/abstract/MED/27895743
http://europepmc.org/abstract/MED/23912084
http://europepmc.org/abstract/MED/25127237
http://europepmc.org/abstract/MED/26378065
http://europepmc.org/abstract/MED/27566247
http://europepmc.org/abstract/MED/11161385
http://europepmc.org/abstract/MED/27432539
http://europepmc.org/abstract/MED/15014009
http://europepmc.org/abstract/MED/23103869
http://europepmc.org/abstract/MED/9892110
http://europepmc.org/abstract/MED/10408907