@article{MZ_1972__128_171798,
     author = {J\"urgen Witte},
     title = {\"Uber {Regularit\"atseigenschaften} der {Potenzr\"aume} eines {Schr\"odinger-Operators} mit singul\"arem {Potential.}},
     journal = {Mathematische Zeitschrift},
     pages = {199--206},
     publisher = {mathdoc},
     volume = {128},
     year = {1972},
     zbl = {0239.35029},
     url = {http://geodesic.mathdoc.fr/item/MZ_1972__128_171798/}
}