References
- Greensher J: Injuries at play. Pediatr Clin North Am 1985; 32(February): 127–139
- A Handbook for Public Playground Safety: Volume I: General Guidelines for New and Existing Playgrounds. Washington, DC, US Consumer Product Safety Commission, 1981
- A Handbook for Public Playground Safety: Volume II: Technical Guidelines for Equipment and Surfacing. Washington, DC, US Consumer Product Safety Commission, 1981