http://europepmc.org/abstract/MED/24755471
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/21901162
http://europepmc.org/abstract/MED/28978093
http://europepmc.org/abstract/MED/26134512
http://europepmc.org/abstract/MED/19679059
http://europepmc.org/abstract/MED/25617745
http://europepmc.org/abstract/MED/25344691
http://europepmc.org/abstract/MED/22810696
http://europepmc.org/abstract/MED/23009572