00407nam a2200133Ia 4500008004100000020001800041050002200059100001600081245006900097260004300166300002100209440003600230521000700266140529s9999    xx            000 0 und d  a9789812839497  aQA 303b.Z63 2011  aZhang, Yao.  aCombinatorial problems in mathematical competitions /cYao Zhang  aSingapore :bWorld Scientific,cc2011.  a289 p. ;c23 cm.  a(Mathematical olympiad series).  aGE