Beyond stimulus cues and reinforcement signals: a new approach to animal metacognition
Journal of Comparative Psychology (2010) - Comment
pubmed: 20836592  doi: 10.1037/a0020129  issn: 1939-2087  issn: 0735-7036 

Justin J. Couchman, Mariana V. C. Coutinho, Michael J. Beran, J. David Smith