@article{MZ_1982__179_173127,
     author = {Richard Haverkamp},
     title = {Approximationsg\"ute der {Ableitungen} bei trigonometrischer {Interpolation.}},
     journal = {Mathematische Zeitschrift},
     pages = {59--68},
     publisher = {mathdoc},
     volume = {179},
     year = {1982},
     zbl = {0458.42004},
     url = {http://geodesic.mathdoc.fr/item/MZ_1982__179_173127/}
}