00263nam a2200109 a 450000500170000002000150001708200180003210000140005024500350006426000310009930000230013020251203090444.0  a0471997412  a515,bDD, Kra  aKrabs, W.  aOptimization and approximation  aNew YorkbJohn-Wileyc1979  axii, 220p., 22 cm.