http://europepmc.org/abstract/MED/8630376
http://europepmc.org/abstract/MED/21504297
http://europepmc.org/abstract/MED/18559874
http://europepmc.org/abstract/MED/10338002
http://europepmc.org/abstract/MED/22237025
http://europepmc.org/abstract/MED/21798259
http://europepmc.org/abstract/MED/25381129
http://europepmc.org/abstract/MED/19322206
http://europepmc.org/abstract/MED/27288520
http://europepmc.org/abstract/MED/19171881
http://europepmc.org/abstract/MED/21399634
http://europepmc.org/abstract/MED/27881874
http://europepmc.org/abstract/MED/26980726
http://europepmc.org/abstract/MED/25381062
http://europepmc.org/abstract/MED/27470916
http://europepmc.org/abstract/MED/16230371
http://europepmc.org/abstract/MED/23702683
http://europepmc.org/abstract/MED/27063598
http://europepmc.org/abstract/MED/22506617
http://europepmc.org/abstract/MED/29253671
http://europepmc.org/abstract/MED/26438511
http://europepmc.org/abstract/MED/27462774
http://europepmc.org/abstract/MED/19536888
http://europepmc.org/abstract/MED/22976956
http://europepmc.org/abstract/MED/27359055
http://europepmc.org/abstract/MED/27276561
http://europepmc.org/abstract/MED/20861915
http://europepmc.org/abstract/MED/21606962
http://europepmc.org/abstract/MED/20442368
http://europepmc.org/abstract/MED/20368469