Landau’s Inequality for Semigroups
Kraljevič and Kurepa in 1970  proved a nice Landau type inequality for semigroups by making use of Taylor’s formula with integral remainder for semigroups, which has been a traditional method for proving such inequalities. The author offers another method in the semigroups and reproves the above result by using his earlier result about Ostrowski inequalities for semigroups, see , Chap. 16, pp. 259–289.
Studies in Systems, Decision and Control
Anastassiou, G. (2021). Landau’s Inequality for Semigroups. Studies in Systems, Decision and Control, 362, 299-307. https://doi.org/10.1007/978-3-030-71481-9_18