@article{100686, author = {Josef Kr\'al}, title = {The Fredholm radius of an operator in potential theory}, journal = {Czechoslovak Mathematical Journal}, volume = {15}, year = {1965}, pages = {454-473}, zbl = {0145.37003}, mrnumber = {0190363}, language = {en}, url = {http://dml.mathdoc.fr/item/100686} }
Král, Josef. The Fredholm radius of an operator in potential theory. Czechoslovak Mathematical Journal, Tome 15 (1965) pp. 454-473. http://gdmltest.u-ga.fr/item/100686/