%0 Journal Article %A Yu. V. Zasorin %T On the well-posedness of Cauchy problems for nonstationary equations with the unselected highest time derivative and the definition of the trace of distribution on the hyperplane of the initial data %J Itogi nauki i tehniki. Sovremennaâ matematika i eë priloženiâ. Tematičeskie obzory %D 2021 %P 47-73 %V 191 %I mathdoc %U http://geodesic.mathdoc.fr/item/INTO_2021_191_a5/ %G ru %F INTO_2021_191_a5