Alfie Kohn (1999). “Punished by Rewards: The Trouble with Gold Stars, Incentive Plans, A's, Praise, and Other Bribes”, p.255, Houghton Mifflin Harcourt
Alfie Kohn (1999). “Punished by Rewards: The Trouble with Gold Stars, Incentive Plans, A's, Praise, and Other Bribes”, p.232, Houghton Mifflin Harcourt
Alfie Kohn (1999). “Punished by Rewards: The Trouble with Gold Stars, Incentive Plans, A's, Praise, and Other Bribes”, p.204, Houghton Mifflin Harcourt
Alfie Kohn (1999). “Punished by Rewards: The Trouble with Gold Stars, Incentive Plans, A's, Praise, and Other Bribes”, p.448, Houghton Mifflin Harcourt