Effects of neonatal handling on playfulness by means of reversal of the desire to play in rats (Rattus norvegicus)
Journal of Comparative Psychology (2009) - Comment
pubmed: 19929103  doi: 10.1037/a0016437  issn: 1939-2087  issn: 0735-7036 

Raúl Aguilar, José M. Caramés, Alfredo Espinet