Statistical Classification of Economic Activities in the European Community (Nace Rev. 2.2)
Lactones n.e.c., heterocyclic compounds with nitrogen hetero-atom(s) only, containing an unfused pyrazole ring, a pyrimidine ring, a piperazine ring, an unfused triazine ring or a phenothiazine ring system not further fused; hydantoin and its derivatives; (21.10.3)