Soares Filho, P. S. D.; Silva, Álvaro J. M.; Velasco, S. M.; Barros, R. S.; Tomanari, G. Y. Assessing Symmetry by Comparing the Acquisition of Symmetric and Nonsymmetric Conditional Relations in a Capuchin Monkey. Int. j. psychol. res. 2016, 9, 30-39.