http://europepmc.org/abstract/MED/21643985
http://europepmc.org/abstract/MED/28869450
http://europepmc.org/abstract/MED/22136423
http://europepmc.org/abstract/MED/20725730
http://europepmc.org/abstract/MED/22199315
http://europepmc.org/abstract/MED/22781348
http://europepmc.org/abstract/MED/20427748
http://europepmc.org/abstract/MED/24877111
http://europepmc.org/abstract/MED/19901110
http://europepmc.org/abstract/MED/24590270
http://europepmc.org/abstract/MED/19636000
http://europepmc.org/abstract/MED/22392125
http://europepmc.org/abstract/MED/23307057
http://europepmc.org/abstract/MED/23370430
http://europepmc.org/abstract/MED/21224364
http://europepmc.org/abstract/MED/27441955
http://europepmc.org/abstract/MED/21829728
http://europepmc.org/abstract/MED/18772396
http://europepmc.org/abstract/MED/21874255
http://europepmc.org/abstract/MED/23184331
http://europepmc.org/abstract/MED/25261925
http://europepmc.org/abstract/MED/22039037
http://europepmc.org/abstract/MED/29683790
http://europepmc.org/abstract/MED/23583981
http://europepmc.org/abstract/MED/24149775
http://europepmc.org/abstract/MED/22591444
http://europepmc.org/abstract/MED/23330999
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/19228619
http://europepmc.org/abstract/MED/28434111
http://europepmc.org/abstract/MED/25652153
http://europepmc.org/abstract/MED/22688054