@article{MZ_1984__187_173511,
     author = {Hermann Engels and Bernd Anton Merschen},
     title = {New {Minimality} {Properties} of {Gaussian} {Quadratures.}},
     journal = {Mathematische Zeitschrift},
     pages = {549--558},
     publisher = {mathdoc},
     volume = {187},
     year = {1984},
     zbl = {0557.41024},
     url = {http://geodesic.mathdoc.fr/item/MZ_1984__187_173511/}
}