http://europepmc.org/abstract/MED/28125452
http://europepmc.org/abstract/MED/19018267
http://europepmc.org/abstract/MED/7669582
http://europepmc.org/abstract/MED/23716351
http://europepmc.org/abstract/MED/23791828
http://europepmc.org/abstract/MED/7852189
http://europepmc.org/abstract/MED/23267135
http://europepmc.org/abstract/MED/10686936
http://europepmc.org/abstract/MED/12694651
http://europepmc.org/abstract/MED/19962665
http://europepmc.org/abstract/MED/17418409
http://europepmc.org/abstract/MED/25846456
http://europepmc.org/abstract/MED/22271473
http://europepmc.org/abstract/MED/29162652
http://europepmc.org/abstract/MED/12648581
http://europepmc.org/abstract/MED/9166952
http://europepmc.org/abstract/MED/12893203
http://europepmc.org/abstract/MED/16867867
http://europepmc.org/abstract/MED/28734796
http://europepmc.org/abstract/MED/23800114
http://europepmc.org/abstract/MED/21926912
http://europepmc.org/abstract/MED/21726664