Pulido Rull, Marco Antonio, Cindy Hernández, Lilian M. Peña, Nora M. Ponce, and Monserrat Rebolledo. “The Operant Conditioning of Letter String Problem Solving”. Mexican Journal of Behavior Analysis 36, no. 3 (November 29, 2010): 55–76. Accessed May 14, 2024. https://revistas.unam.mx/index.php/rmac/article/view/21375.