Madrigal, K.D., Flores, C.J. y Hernández, C.M. 2019. The effects of unsignaled and signaled delays of reinforcement in rats: A between-procedures comparison. Revista Mexicana de Análisis de la Conducta. 44, 2 (feb. 2019). DOI:https://doi.org/10.5514/rmac.v44.i2.68537.