Changes made by 91/664/EEC: Council Decision of 11 December 1991 designating the Community reference laboratories for testing certain substances for residues
EU Decision 1991/664
No changes made by 91/664/EEC: Council Decision of 11 December 1991 designating the Community reference laboratories for testing certain substances for residues are recorded.
From legislation.gov.uk's record of changes, the official one: see it there.