Todorov, J. C., L. C. Ferreira de Carvalho, and P. R. Meira Menandro. “The estándar Sidman Avoidance Procedure As a Temporal Differentiation Schedule”. Mexican Journal of Behavior Analysis, vol. 3, no. 2, Jan. 2011, pp. 151-60, doi:10.5514/rmac.v3.i2.23628.