Williams, Dean C., Yusuke Hayashi, Adam Brewer, Kathryn J. Saunders, Stephen Fowler, and Raymond C. Pitts. 2019. “Transitions from Rich-to-Lean Schedules Increase Attack in a Laboratory Model of Social Aggression in Pigeons: I. Fixed-Ratio Schedules”. Mexican Journal of Behavior Analysis 45 (2). https://doi.org/10.5514/rmac.v45.i2.75580.