%0 Journal Article %T Zprávy %J Applications of Mathematics %D 1973 %P 140 %V 18 %N 2 %U http://geodesic.mathdoc.fr/articles/10.21136/AM.1973.103462/ %R 10.21136/AM.1973.103462 %G cs %F 10_21136_AM_1973_103462