Changes to Pensions Increase (Local Authorities' etc. Pensions) 1974
S.I. 1974/1740
Made by Pensions Increase (Local Authorities' etc. Pensions) 1989
3 changes. All changes to Pensions Increase (Local Authorities' etc. Pensions) 1974
From legislation.gov.uk's record of changes, the official one: see it there.