http://europepmc.org/abstract/MED/12007715
http://europepmc.org/abstract/MED/11159175
http://europepmc.org/abstract/MED/23774526
http://europepmc.org/abstract/MED/8483937
http://europepmc.org/abstract/MED/9349508
http://europepmc.org/abstract/MED/8286219
http://europepmc.org/abstract/MED/7946294
http://europepmc.org/abstract/MED/15656799
http://europepmc.org/abstract/MED/9622088
http://europepmc.org/abstract/MED/8631591
http://europepmc.org/abstract/MED/25759020
http://europepmc.org/abstract/MED/1617650
http://europepmc.org/abstract/MED/15145527
http://europepmc.org/abstract/MED/11078762
http://europepmc.org/abstract/MED/11981662
http://europepmc.org/abstract/MED/8437842
http://europepmc.org/abstract/MED/12447615
http://europepmc.org/abstract/MED/8151121
http://europepmc.org/abstract/MED/28368926
http://europepmc.org/abstract/MED/8261448
http://europepmc.org/abstract/MED/8319200
http://europepmc.org/abstract/MED/18070208
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/25759019