00270nam a2200109Ia 4500008004100000082001700041100001900058245003100077250001200108260003200120300000800152240913s9999||||xx |||||||||||||| ||und||  a512.7  DAV/E  aDavid M.Burton 0aElementary  Number  Theory  a7th Ed.  bMc Graw- HillaLondonc2013  a436