00291nam a2200109 a 450000500170000002000180001708200150003510000330005024500310008326000420011430000250015620251203110850.0  a9780199227303  a512.7bVIL  aVillegas, Fernando Rodriguez  aExperimental number theory  aOxfordbOxford University Pressc2007  axvi, 214p.c24cm. PB