K. R. Alves, A. C. Goulart, R. M. Ladeira, I. R. S. de Oliveira, and I. M. Benseñor, “Frequency of cholecystectomy and associated sociodemographic and clinical risk factors in the ELSA-Brasil study”, Sao Paulo Med J, vol. 134, no. 3, pp. 240–250, Jun. 2016.