http://europepmc.org/abstract/MED/8408453
http://europepmc.org/abstract/MED/29615459
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/24423316
http://europepmc.org/abstract/MED/28351340
http://europepmc.org/abstract/MED/25862857