@article{bwmeta1.element.desklight-10320d9f-6f35-43e8-92f5-50c628f23f2e,
author = {W. D\"uck},
title = {Variationsprinzipien bei nat\"urlichen Eigenwertproblemen},
journal = {Annales Polonici Mathematici},
volume = {17},
year = {1965},
pages = {79-115},
zbl = {0138.32804},
language = {deu},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.desklight-10320d9f-6f35-43e8-92f5-50c628f23f2e}
}
W. Dück. Variationsprinzipien bei natürlichen Eigenwertproblemen. Annales Polonici Mathematici, Tome 17 (1965) pp. 79-115. http://gdmltest.u-ga.fr/item/bwmeta1.element.desklight-10320d9f-6f35-43e8-92f5-50c628f23f2e/