00336nam a2200121Ia 4500082002000000100002200020245007300042260003400115300001600149490003900165500000500204700000500209  a515.73bD511.AC  aDevore, Ronald A.  aApproximation of continuous functions by positive linear operatorsb  aBerlinbSpringer-Verlagc1972  aviii, 289p.  aLecture notes in Mathematicsv 293  a  a