http://europepmc.org/abstract/MED/20678218
http://europepmc.org/abstract/MED/19388938
http://europepmc.org/abstract/MED/15613106
http://europepmc.org/abstract/MED/12393679
http://europepmc.org/abstract/MED/14615365
http://europepmc.org/abstract/MED/12399980
http://europepmc.org/abstract/MED/27884971
http://europepmc.org/abstract/MED/24047651
http://europepmc.org/abstract/MED/20520634
http://europepmc.org/abstract/MED/17910630
http://europepmc.org/abstract/MED/27029036
http://europepmc.org/abstract/MED/24523240
http://europepmc.org/abstract/MED/24850867
http://europepmc.org/abstract/MED/22417201
http://europepmc.org/abstract/MED/24030381
http://europepmc.org/abstract/MED/25177364
http://europepmc.org/abstract/MED/27127180
http://europepmc.org/abstract/MED/15180860