@article{MM2_1970__3_154010,
     author = {Heinz-Dieter Niessen},
     title = {Singul\"are {S-hermitische} {Rand-Eigenwertprobleme.}},
     journal = {Manuscripta mathematica},
     pages = {35--68},
     publisher = {mathdoc},
     volume = {3},
     year = {1970},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MM2_1970__3_154010/}
}