http://europepmc.org/abstract/MED/1390233
http://europepmc.org/abstract/MED/22976956
http://europepmc.org/abstract/MED/24831771
http://europepmc.org/abstract/MED/8824725
http://europepmc.org/abstract/MED/25652455
http://europepmc.org/abstract/MED/27288520
http://europepmc.org/abstract/MED/16059649
http://europepmc.org/abstract/MED/27276561
http://europepmc.org/abstract/MED/20404136
http://europepmc.org/abstract/MED/26438511
http://europepmc.org/abstract/MED/23210734
http://europepmc.org/abstract/MED/27029036
http://europepmc.org/abstract/MED/2040694
http://europepmc.org/abstract/MED/27881874
http://europepmc.org/abstract/MED/8551805
http://europepmc.org/abstract/MED/8037181
http://europepmc.org/abstract/MED/23153540
http://europepmc.org/abstract/MED/25412851
http://europepmc.org/abstract/MED/7654857
http://europepmc.org/abstract/MED/8217795