%0 Journal Article %A Staněk, Svatoslav %T A phase of the differential equation $y'=Q(t)y$ with a complex coefficient $Q$ of the real variable %J Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica %D 1986 %P 57-75 %V 25 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/AUPO_1986__25_1_a3/ %G en %F AUPO_1986__25_1_a3