Changes made by Commission Regulation (EEC) No 339/80 of 13 February 1980 amending Regulation (EEC) No 2831/79 as regards the possibility of terminating short-term storage contracts for grape must and concentrated grape must at the time of the conclusion of a long-term contract: Commission Regulation (EEC) No 2831/79 of 14 December 1979 authorizing the conclusion of long-term private storage contracts for grape must and concentrated grape must in respect of the 1979/80 wine year