http://europepmc.org/abstract/MED/12915879
http://europepmc.org/abstract/MED/7904314
http://europepmc.org/abstract/MED/10995889
http://europepmc.org/abstract/MED/20668451
http://europepmc.org/abstract/MED/22610119
http://europepmc.org/abstract/MED/27148695
http://europepmc.org/abstract/MED/7604888
http://europepmc.org/abstract/MED/25232177
http://europepmc.org/abstract/MED/16941491
http://europepmc.org/abstract/MED/7961118
http://europepmc.org/abstract/MED/9815823
http://europepmc.org/abstract/MED/7872719
http://europepmc.org/abstract/MED/26000489
http://europepmc.org/abstract/MED/7542226
http://europepmc.org/abstract/MED/15541116