http://europepmc.org/abstract/MED/22526905
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/24747642
http://europepmc.org/abstract/MED/28973495
http://europepmc.org/abstract/MED/15922892
http://europepmc.org/abstract/MED/17289876
http://europepmc.org/abstract/MED/23585556
http://europepmc.org/abstract/MED/8509216
http://europepmc.org/abstract/MED/27589897