1. G. D. Allen, C. K. Chui, W. R. Madych, F.J. Nacowich, P. W. Smith,Padé approximation of Stieltjes series, J. Approx. Theory14 (1975), 302–316.
2. G. A. Baker, Jr., P. Graves-Morris,Padé approximants, part I: basic theory 1981. Addison-Wesley, Reading, Mass.
3. D. Galant,An implementation of Christoffel's theorem in the theory of orthogonal polynomials, Math. Comp.25 (1971), 111–113.
4. W. Gautschi,A survey of Gauss-Christoffel quadrature formulae, in «E. B. Christoffel, The Influence of his Work on Mathematics and the Physical Sciences» 1981. P. L. Butzer, F. Fehér, eds. Birkhäuser, Basel, 72–147.
5. Internat. Ser. Numer. Math.;W. Gautschi,1982