(1968). About the Sudbury Valley School. Sudbury Valley School.
Chicago-viite (17. p.)About the Sudbury Valley School. [Framingham]: Sudbury Valley School, 1968.
MLA-viite (8. p.)About the Sudbury Valley School. Sudbury Valley School, 1968.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.