http://europepmc.org/abstract/MED/9751632
http://europepmc.org/abstract/MED/18464243
http://europepmc.org/abstract/MED/28825729
http://europepmc.org/abstract/MED/16575872
http://europepmc.org/abstract/MED/30155617
http://europepmc.org/abstract/MED/22470196
http://europepmc.org/abstract/MED/25670083
http://europepmc.org/abstract/MED/8019557