Changes to Council Regulation (EEC, Euratom, ECSC) No 2859/77 of 19 December 1977 adjusting the remuneration and pensions of officials and other servants of the European Communities and the weightings applied thereto
EU Regulation No 2859/1977
Made by Council Regulation (Euratom, ECSC, EEC) No 1461/78 of 26 June 1978 adjusting the weightings applied to the remuneration and pensions of officials and other servants of the European Communities
From legislation.gov.uk's record of changes, the official one: see it there.