1,2,3-Oxadiazolium,3-[2-[[(6R,7R)-2-carboxy-3-[[(5-methyl-1,3,4-thiadiazol-2-yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl]amino]-2-oxoethyl]-5-hydroxy-,inner salt, monosodium salt (9CI); Sydnone,3-[2-[[2-carboxy-3-[[(5-methyl-1,3,4-thiadiazol-2-yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl]amino]-2-oxoethyl]-,monosodium salt, (6R-trans)-; Sydnone,3-[[[2-carboxy-3-[[(5-methyl-1,3,4-thiadiazol-2-yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl]carbamoyl]methyl]-,monosodium salt (8CI); 1,2,3-Oxadiazolium,3-[2-[[2-carboxy-3-[[(5-methyl-1,3,4-thiadiazol-2-yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl]amino]-2-oxoethyl]-5-hydroxy-,inner salt, monosodium salt, (6R-trans)-; Cefanone; Cephanone; Sodium3-(5-methyl-1,3,4-thiadiazol-2-ylthiomethyl)-7-[2-(3-sydnone)acetamido]-3-cephem-4-carboxylate