@book{13495,
	author = {Devore, Ronald A. and Lorentz, George G. and Lorentz, George G. ; jt. auth.},
	title = {Constructive approximation},
	publisher = {Springer-Verlag},
	year = {1993},
	series = {Die Grundlehren der mathematischen Wissenschaften},
	address = {Berlin}
}