http://europepmc.org/abstract/MED/19435942
http://europepmc.org/abstract/MED/8548755
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/29683790
http://europepmc.org/abstract/MED/24705251
http://europepmc.org/abstract/MED/8857999
http://europepmc.org/abstract/MED/8760309
http://europepmc.org/abstract/MED/26919320
http://europepmc.org/abstract/MED/9098651