Commission Regulation (EEC) No 1721/79 of 3 August 1979 re-establishing the levying of customs duties on umbrellas and sunshades (including walking-stick umbrellas, umbrella tents, and garden and similar umbrellas), falling within heading No 66.01 and originating in developing countries, to which the preferential tariff arrangements set out in Council Regulation (EEC) No 3156/78 apply