http://europepmc.org/abstract/MED/23323158
http://europepmc.org/abstract/MED/25471051
http://europepmc.org/abstract/MED/11801559
http://europepmc.org/abstract/MED/24767714
http://europepmc.org/abstract/MED/23161787
http://europepmc.org/abstract/MED/10323080
http://europepmc.org/abstract/MED/25257301
http://europepmc.org/abstract/MED/21971842
http://europepmc.org/abstract/MED/20068183
http://europepmc.org/abstract/MED/8878451
http://europepmc.org/abstract/MED/7728764
http://europepmc.org/abstract/MED/25667294