1. Einige Ungleichungen für zweimal differentierbare Funktionen;Landau,1913
2. On inequalities between the upper bounds of the successive derivatives of an arbitrary functions on an infinite interval;Kolmogorov;Amer. Math. Soc. Transl. Ser. 1,1962
3. Solution of Landau's problem concerning higher derivatives on the halfline;Schoenb́erg,1970
4. Inequalities;Polya,1934