Pendekatan untuk Pendidikan Lingkungan yang Berkelanjutan

(Wals, Arjen E. J., Floor Geerling-Eijff, Francisca Hubeek, Sandra van der Kroon, dan Janneke Vader. 2008. All Mixed Up? Instrumental and Emancipatory Learning Toward a More Sustainable World: Considerations for EE Policymakers. Applied Environmental Education and Communication 7: 55-65.)