7 -[D.alpha.-(4-Hydroxy-1,5-naphthyridine-3-carboxamido)-.alpha.

7(2-Phenyl or thienyl-2-isonicotinoyloxyacetamido)-3-(1-methyl-1

7,7'-Diamino derivatives of 2,2'-spirodibenzopyranes

7,8-Dihydro-2,5 ,8-trisubstituted-7-oxo-pyrido[2,3-d]-pyrimidine

7,8-Dihydro-2,5,8- trisubstituted-7-oxo-pyrido[2,3-d]pyrimidine-

7-(.alpha.-SUBSTITUTED GLYCINAMIDO)-3-SUBSTITUTED METHYL-3-CEPHE

7-(.alpha.-Substituted glycinamido)-3-substituted methyl-3-cephe

7-(.alpha.-Sulfoacylamido)cephalosporins

7-(.beta.-Aminoac ylamino)-3-heterocyclic-thiomethyl-3-cephem-4-

7-(.beta.-Aminoacylamino)-3-substituted-3-cephem-4-carboxylic ac

7-(1,3-Dithiolan-2-imino)cephalosporanic acid derivatives

7-(1,3-Dithiolan-2-imino)cephalosporanic acid derivatives

7-(2,3-Dihydrobenzo-5-furanyl)-acetamido cephalosporin derivativ

7-(2-(Substituted benzoyl)amino)acetamido)cephalosporins

7-(2-Amino-4-thiazolyl)-acetamido cephalosporanic acids

7-(5-Amino-5-carboxyvaler-amido)-3-(carbamoyloxymethyl)-7-methox

7-(5-Amino-5-carboxyvaleramido)-7-methoxycephalosporanic acid

7-(Amidinothio)acetamido-7-methoxy cephalosporins

7-(Carboxy substituted .alpha.-etherified oximino arylacetamido)

7-(D-.alpha.-Hydroxy-2-arylacetamido)-3-(2-carboxyalkyl-2,3-dihy