@article{JRAM_1973__261_151335,
     author = {Heinz-Dieter Niessen},
     title = {Greensche {Matrix} und die {Formel} von {Titchmarsh-Kodaira} f\"ur singul\"are {S-hermitesche} {Eigenwertprobleme.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {164--193},
     publisher = {mathdoc},
     volume = {261},
     year = {1973},
     zbl = {0269.34017},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1973__261_151335/}
}