@article{MM2_1973__8_154149,
     author = {Walter Trebels},
     title = {\"Uber {Jackson-} und {Bernstein-Typ} {Ungleichungen} f\"ur lineare {Approximationsverfahren} in {Lp} {(En).}},
     journal = {Manuscripta mathematica},
     pages = {287--318},
     publisher = {mathdoc},
     volume = {8},
     year = {1973},
     zbl = {0252.41018},
     url = {http://geodesic.mathdoc.fr/item/MM2_1973__8_154149/}
}