Romina M. Barros, Ellen J. Silver, and Ruth E. K. Stein, “School Recess and Group Classroom Behavior,” Pediatrics 123, no. 2 (2009): 431–436; Anthony D. Pellegrini and Catherine M. Bohn, “The Role of Recess in Children’s Cognitive Performance and School Adjustment,” Educational Researcher 34, no. 1 (2005): 13–19.