%0 Journal Article %A Král, Josef %A Medková, Dagmar %T Essential norms of a potential theoretic boundary integral operator in $L\sp 1$ %J Mathematica Bohemica %D 1998 %P 419-436 %V 123 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.21136/MB.1998.125966/ %R 10.21136/MB.1998.125966 %G en %F 10_21136_MB_1998_125966