http://europepmc.org/abstract/MED/27149842
http://europepmc.org/abstract/MED/27863258
http://europepmc.org/abstract/MED/24755471
http://europepmc.org/abstract/MED/23700467
http://europepmc.org/abstract/MED/26648449
http://europepmc.org/abstract/MED/28002797