http://europepmc.org/abstract/MED/27284958
http://europepmc.org/abstract/MED/17545528
http://europepmc.org/abstract/MED/30181556
http://europepmc.org/abstract/MED/27535334
http://europepmc.org/abstract/MED/28481359
http://europepmc.org/abstract/MED/28905136
http://europepmc.org/abstract/MED/7861463
http://europepmc.org/abstract/MED/25746663
http://europepmc.org/abstract/MED/29349598
http://europepmc.org/abstract/MED/28027327
http://europepmc.org/abstract/MED/24398047
http://europepmc.org/abstract/MED/9102207