Changes made by ECSC High Authority: Decision No 3/58 of 18 March 1958 on alignment of prices for sales of coal in the common market
EU Decision 1958/3
No changes made by ECSC High Authority: Decision No 3/58 of 18 March 1958 on alignment of prices for sales of coal in the common market are recorded.
From legislation.gov.uk's record of changes, the official one: see it there.