%0 Journal Article %A Jan Bochenek %T On some problems in the theory of eigenvalues and eigenfunctions associated with linear elliptic partial differential equations of the second order %J Annales Polonici Mathematici %D 1964 %P 153-167 %V 16 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/ap-16-2-153-167/ %R 10.4064/ap-16-2-153-167 %G en %F 10_4064_ap_16_2_153_167