http://europepmc.org/abstract/MED/1996309
http://europepmc.org/abstract/MED/27630302
http://europepmc.org/abstract/MED/22980975
http://europepmc.org/abstract/MED/21227397
http://europepmc.org/abstract/MED/27105513
http://europepmc.org/abstract/MED/1581907
http://europepmc.org/abstract/MED/23515407
http://europepmc.org/abstract/MED/9858914
http://europepmc.org/abstract/MED/25376516
http://europepmc.org/abstract/MED/18948947
http://europepmc.org/abstract/MED/27923066
http://europepmc.org/abstract/MED/2197591
http://europepmc.org/abstract/MED/22975805
http://europepmc.org/abstract/MED/26164066
http://europepmc.org/abstract/MED/24700479
http://europepmc.org/abstract/MED/26826182
http://europepmc.org/abstract/MED/17671710
http://europepmc.org/abstract/MED/29681454
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/20668451
http://europepmc.org/abstract/MED/23371856
http://europepmc.org/abstract/MED/12460918