A. M. E. de B. L. Martins, M. F. Silveira, C. V. de Freitas, N. B. Eleutério, P. H. A. Oliveira, and R. C. Ferreira, “Challenges of a calibration process for an epidemiological study involving quantitative and ordinal categorical variables: one example”, Arq Odontol, vol. 47, no. 4, May 2016.