http://europepmc.org/abstract/MED/26900293
http://europepmc.org/abstract/MED/27149842
http://europepmc.org/abstract/MED/24755471
http://europepmc.org/abstract/MED/22327622
http://europepmc.org/abstract/MED/26648449
http://europepmc.org/abstract/MED/9674699
http://europepmc.org/abstract/MED/8700220
http://europepmc.org/abstract/MED/22987205
http://europepmc.org/abstract/MED/28577310
http://europepmc.org/abstract/MED/20565851
http://europepmc.org/abstract/MED/27302833
http://europepmc.org/abstract/MED/10959092
http://europepmc.org/abstract/MED/16902769
http://europepmc.org/abstract/MED/10674020