1. Formules de cubatures mecaniques a coefficients non negatifs;Tchakaloff;Bull. sci. math., ser. 2,1957
2. A construction of non-negative approximate quadratures;Davis;Math. Comput.,1967
3. Approximate integration rules with non-negative weights;Davis,1969
4. Uniform approximation of non-negative continuous linear functionals;Wilson;J. Approximation Theory,1969
5. Interpolation cubature formulas and orthogonal polynomials;Mysovskikh,1972