A connection between two certain methods of successive approximations in differential equations C. Olech — 1962 Annales Polonici Mathematici
Sur certaines propriétés des intégrales de l'équation y'=f(x,y) dont le second membre est doublement périodique C. Olech — 1957 Annales Polonici Mathematici
On the asymptotic coincidence of sets filled up by integrals of two systems of ordinary differential equations C. Olech — 1961 Annales Polonici Mathematici
An optimal solution of Nicoletti's boundary value problem A. Lasota; C. Olech — 1966 Annales Polonici Mathematici
Monotonicity assumption in uniqueness criteria for differential equations C. Olech; A. Pliś — 1967 Colloquium Mathematicae
Contribution à la théorie de la formule simpsonienne des quadratures approchées Stanisław Gołąb; C. Olech — 1955 Annales Polonici Mathematici
Integration of infinite systems of differential inequalities W. Mlak; C. Olech — 1963 Annales Polonici Mathematici