9Ascher G. , Process for the production of known 2 - oximinoacetamido -3 - cephem -4 - earboxylic derivatives comprising acylation of 7 - amino - 3 - cephem - 4 - carboxylic acid derivatives with novel 2 - oximinoacetic acid thio esters, as well as such thioesters and their production : US,4767852 [P]. 1988 -08 - 30.
