http://europepmc.org/abstract/MED/23417712
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/26496030
http://europepmc.org/abstract/MED/29683790
http://europepmc.org/abstract/MED/17404084
http://europepmc.org/abstract/MED/25078279