http://europepmc.org/abstract/MED/9047388
http://europepmc.org/abstract/MED/24710824
http://europepmc.org/abstract/MED/12118338
http://europepmc.org/abstract/MED/11435176
http://europepmc.org/abstract/MED/10675493
http://europepmc.org/abstract/MED/26934577
http://europepmc.org/abstract/MED/10694947
http://europepmc.org/abstract/MED/24292195
http://europepmc.org/abstract/MED/27693639
http://europepmc.org/abstract/MED/24436120
http://europepmc.org/abstract/MED/10389982
http://europepmc.org/abstract/MED/8986966
http://europepmc.org/abstract/MED/24662767
http://europepmc.org/abstract/MED/11255261
http://europepmc.org/abstract/MED/10766393
http://europepmc.org/abstract/MED/27050151
http://europepmc.org/abstract/MED/21798893
http://europepmc.org/abstract/MED/19101490
http://europepmc.org/abstract/MED/21798897
http://europepmc.org/abstract/MED/16608795
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/8945609
http://europepmc.org/abstract/MED/17340131