1. On a method of approximate integration by S.A. Chaplygin;Luzin;Uspekhi Math. Nauk.,1951
2. New Method of Approximate Integration of Differential Equations;Chaplygin,1950
3. Differential Equations;Tricomi,1961
4. Introduction to the Theory of Functional Differential Equations;Azbelev,1991
5. The converse of a theorem on differential inequalities;Wilkins;Bull. Amer. Math. Soc.,1947