{HEAD ~ This invention} provides novel pyridonecarboxylic acid derivatives having {TAIL ~ a quite high antimicrobial activity} 
{ HEAD ~ This invention } provides novel pyridonecarboxylic acid derivatives having { TAIL ~ a quite high antimicrobial activity }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL