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• [1] F. Altomare, M. Campiti, Korovkin-type Approximation Theory and its Applications, De Gruyter Studies in Mathematics 17, W. De Gruyter, Berlin-New York, 1994.
• [2] F. Altomare, M. Cappelletti Montano, V. Leonessa and I. Ra¸sa, Markov Operators, Positive Semigroups and Approximation Processes, de Gruyter Studies in Mathematics 61, de Gruyter, Berlin/Boston, 2014.
• [3] A. Attalienti, M. Campiti, Semigroups generated by ordinary differential operators in L1(I), Positivity 8 (1) (2004), 11–30.
• [4] M. Campiti, S. P. Ruggeri, Approximation of semigroups and cosine functions in spaces of periodic functions, Applicable Analysis 86 (2) (2007), 167–186.
• [5] Ph. Clément, C. A. Timmermans, On C0-semigroups generated by differential operators satisfying Ventcel’s boundary conditions, Indag. Math. 89 (1986), 379–387.
• [6] K.-J. Engel, R. Nagel, One-parameter semigroups for linear evolution equations, Graduate Text in Mathematics 194, Springer, New York, 2000.
• [7] W. Feller, The parabolic differential equations and the associated semi-groups of transformations, Annals of Math. 55 (3) (1952), 468–519.
• [8] P. Mandl, Analytical treatment of one-dimensional Markov processes, Die Grundlehren der mathematischen Wissenschaften in Einzeldarstellungen 151, Springer-Verlag, Berlin-Heidelberg-New York, 1969.
• [9] C. A. Timmermans, On C0-semigroups in a space of bounded continuous functions in the case of entrance or natural boundary points. In: Gòmez-Fernandez J.A., Guerra-Vázquez F., Lòpez-Lagomasino G., Jiménez-Pozo M.A. (eds). Approximation and Optimization, Lecture Notes in Mathematics, 1354. Springer, Berlin, Heidelberg, 2006.