http://europepmc.org/abstract/MED/16878328
http://europepmc.org/abstract/MED/10504528
http://europepmc.org/abstract/MED/10849331
http://europepmc.org/abstract/MED/19561568
http://europepmc.org/abstract/MED/27109316
http://europepmc.org/abstract/MED/11992546
http://europepmc.org/abstract/MED/9160316
http://europepmc.org/abstract/MED/22693489
http://europepmc.org/abstract/MED/16261586
http://europepmc.org/abstract/MED/20598147
http://europepmc.org/abstract/MED/9247632
http://europepmc.org/abstract/MED/18580682
http://europepmc.org/abstract/MED/11064357
http://europepmc.org/abstract/MED/12935923
http://europepmc.org/abstract/MED/10398127
http://europepmc.org/abstract/MED/9824209
http://europepmc.org/abstract/MED/18300804
http://europepmc.org/abstract/MED/22559980
http://europepmc.org/abstract/MED/20712646
http://europepmc.org/abstract/MED/17000668
http://europepmc.org/abstract/MED/16519562
http://europepmc.org/abstract/MED/8401579
http://europepmc.org/abstract/MED/22406360
http://europepmc.org/abstract/MED/18408594
http://europepmc.org/abstract/MED/18333903
http://europepmc.org/abstract/MED/16517477
http://europepmc.org/abstract/MED/16021514