(1991). Environmental labelling in OECD countries. Paris: Organization for economic co-operation and development.
Παραπομπή Chicago StyleEnvironmental Labelling in OECD Countries. Paris: Organization for economic co-operation and development, 1991.
Παραπομπή MLAEnvironmental Labelling in OECD Countries. Paris: Organization for economic co-operation and development, 1991.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.