http://europepmc.org/abstract/MED/11306511
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/24141649
http://europepmc.org/abstract/MED/8312582
http://europepmc.org/abstract/MED/27135926
http://europepmc.org/abstract/MED/10706127
http://europepmc.org/abstract/MED/16959974