@article{AM2_1989__38_1_137311,
     author = {G. Sottas},
     title = {On the positivity of ultraspherical type quadrature formulas with {Jacobi} abscissas.},
     journal = {Aequationes mathematicae},
     pages = {10--27},
     publisher = {mathdoc},
     volume = {38},
     number = {1},
     year = {1989},
     zbl = {0683.41039},
     url = {http://geodesic.mathdoc.fr/item/AM2_1989__38_1_137311/}
}