@article{NUMA_1971__17_132082,
     author = {D. BRAESS},
     title = {Chebyshev {Approximation} by {Spline} {Functions} with {Free} {Knots.}},
     journal = {Numerische Mathematik},
     pages = {357--366},
     publisher = {mathdoc},
     volume = {17},
     year = {1971},
     zbl = {0227.65010},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1971__17_132082/}
}