Raghunathan K, Layton JB, Ohnuma T, Shaw AD. Observational research using propensity scores. Adv Chronic Kidney Dis. 2016 Nov;23(6):367-72. doi: 10.1053/j.ackd.2016.11.010
Graham JE, Rouse M, Twiss J, McKenna SP, Vidalis AA. Greek adaptation and validation of the Ankylosing Spondylitis Quality of Life (ASQoL) measure. Hippokratia. 2015;19(2):119-24.