Changes made by 77/293/EEC: Commission Decision of 18 April 1977 amending the Commission Decision of 30 March 1977 on certain measures to prevent the spread of classical swine fever
EU Decision 1977/293
Made to Commission Decision of 30 March 1977 concerning certain measures to prevent the spread of classical swine fever
From legislation.gov.uk's record of changes, the official one: see it there.