Heimlich, J. E. (2002). Environmental education: A resource handbook. Phi Delta Kappa EducationalFoundation.
Chicago (17e ed.) BronvermeldingHeimlich, Joe E. Environmental Education: A Resource Handbook. Estados Unidos: Phi Delta Kappa EducationalFoundation, 2002.
MLA (9e ed.) BronvermeldingHeimlich, Joe E. Environmental Education: A Resource Handbook. Phi Delta Kappa EducationalFoundation, 2002.
Let op: Deze citaties zijn niet altijd 100% accuraat.