@article{ELMA_1973__28_141101,
     author = {B. Herz and J. Kaapke},
     title = {Ein isoperimetrisches {Problem} mit {Nebenbedingung.}},
     journal = {Elemente der Mathematik},
     pages = {63--65},
     publisher = {mathdoc},
     volume = {28},
     year = {1973},
     zbl = {0255.52005},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1973__28_141101/}
}