00317nam a22001217a 4500020001800000100001800018245006200036260002900098300001200127650001300139650002400152700001900176  a9783111700700  aJespers, Eric  aGroup ring groupsbVol.2 structure theorms of unit groups  aBerlinbDe Gruyterc2025  ax+217p.  aK theory  aHyperbolic geometry  aRio, Angel del