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
Aranda E, Aparicio J, Alonso V, Garcia-Albeniz X, Garcia-Alfonso P, Salazar R, Valladares M, Vera R, Vieitez JM, Garcia-Carbonero R. SEOM clinical guidelines for diagnosis and treatment of metastatic colorectal cancer 2015. Clin Transl Oncol. 2015 Dec;17(12):972-81. doi: 10.1007/s12094-015-1434-4
Rothman KJ, Glass RL, Espinal F, Velez H. Caries-free teeth in the absence of fluoride ion. J Public Health Dent. 1972;32(4):225-8. doi: 10.1111/j.1752-7325.1972.tb03977.x