@article{MM2_1978__26_154577,
     author = {Michael Langenbruch},
     title = {Randverteilungen von {Null\"osungen} hypoelliptischer {Differentialgleichungen.}},
     journal = {Manuscripta mathematica},
     pages = {17--36},
     publisher = {mathdoc},
     volume = {26},
     year = {1978},
     zbl = {0391.35017},
     url = {http://geodesic.mathdoc.fr/item/MM2_1978__26_154577/}
}