%0 Journal Article %A M. O. Korpusov %A A. A. Panin %A A. E. Shishkov %T On the critical exponent ``instantaneous~blow-up'' versus ``local solubility'' in the Cauchy~problem for a~model equation of Sobolev type %J Izvestiya. Mathematics %D 2021 %P 111-144 %V 85 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM2_2021_85_1_a4/ %G en %F IM2_2021_85_1_a4