REFERENCES
- Fisher , W. W. , Piazza , C. C. , & Roane , H. S. ( Eds.). (2011 ). Handbook of applied behavior analysis . New York , NY : Guilford .
- Premack , D. ( 1959 ). Toward empirical behavioral laws: 1. Positive reinforcement . Psychological Record , 66 , 219 – 233 .