Hess, F. M. (2010). Education unbound: The promise and practice of greenfield schooling. ASCD.
Lua i Stíl Chicago (17ú heag.)Hess, Frederick M. Education Unbound: The Promise and Practice of Greenfield Schooling. Alexandria, VA: ASCD, 2010.
Lua MLA (9ú heag.)Hess, Frederick M. Education Unbound: The Promise and Practice of Greenfield Schooling. ASCD, 2010.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.