http://europepmc.org/abstract/MED/1350261
http://europepmc.org/abstract/MED/9834286
http://europepmc.org/abstract/MED/9399746
http://europepmc.org/abstract/MED/10323884
http://europepmc.org/abstract/MED/8160776
http://europepmc.org/abstract/MED/28524162
http://europepmc.org/abstract/MED/8039618
http://europepmc.org/abstract/MED/1973170