Unesco-UNEP International Environmental Education Programme & Grabe, S. (1987). Environmental education in technical and vocational education. Unesco.
Παραπομπή σε μορφή Chicago (17η εκδ.)Unesco-UNEP International Environmental Education Programme και Sven Grabe. Environmental Education in Technical and Vocational Education. Paris: Unesco, 1987.
Παραπομπή σε μορφή MLA (9th εκδ.)Unesco-UNEP International Environmental Education Programme και Sven Grabe. Environmental Education in Technical and Vocational Education. Unesco, 1987.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.