http://europepmc.org/abstract/MED/14734474
http://europepmc.org/abstract/MED/10949938
http://europepmc.org/abstract/MED/19435942
http://europepmc.org/abstract/MED/8548755
http://europepmc.org/abstract/MED/8552400
http://europepmc.org/abstract/MED/7987828
http://europepmc.org/abstract/MED/24695838
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/11355302
http://europepmc.org/abstract/MED/29683790
http://europepmc.org/abstract/MED/7987825
http://europepmc.org/abstract/MED/8857999
http://europepmc.org/abstract/MED/8760309
http://europepmc.org/abstract/MED/11303791
http://europepmc.org/abstract/MED/7478535
http://europepmc.org/abstract/MED/12744472
http://europepmc.org/abstract/MED/7887443
http://europepmc.org/abstract/MED/9098651
http://europepmc.org/abstract/MED/9334810
http://europepmc.org/abstract/MED/25740784
http://europepmc.org/abstract/MED/8674005