http://europepmc.org/abstract/MED/25846456
http://europepmc.org/abstract/MED/11244334
http://europepmc.org/abstract/MED/15221786
http://europepmc.org/abstract/MED/7547235
http://europepmc.org/abstract/MED/25846551
http://europepmc.org/abstract/MED/11595686
http://europepmc.org/abstract/MED/16183105
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/9550561
http://europepmc.org/abstract/MED/25986173
http://europepmc.org/abstract/MED/26257827
http://europepmc.org/abstract/MED/7852189
http://europepmc.org/abstract/MED/1516069
http://europepmc.org/abstract/MED/8481915
http://europepmc.org/abstract/MED/15099937