Yuguero O, Marsal JR, Buti M, Esquerda M, Soler-Gonzalez J. Descriptive study of association between quality of care and empathy and burnout in primary care. BMC Med Ethics. 2017 Sep 26;18(1):54. doi: 10.1186/s12910-017-0214-9
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
Chatzi L, Torrent M, Romieu I, Garcia-Esteban R, Ferrer C, Vioque J, Kogevinas M, Sunyer J. Diet, wheeze, and atopy in school children in Menorca, Spain. Pediatr Allergy Immunol. 2007 Sep;18(6):480-5. doi: 10.1111/j.1399-3038.2007.00596.x