European Commission, State of play in the EU on GM-free food labelling schemes and assessment of the need for possible harmonisation, Final report, 2013-10, p. ix, Glossary, "Positive labelling vs. negative labelling" ([Internet, 2019-11-25](https://ec.europa.eu/food/sites/food/files/plant/docs/gmo-traceability-gm-final_report_en.pdf))