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Novati,\nFast and accurate approximations to fractional powers of operators,\nIMA J. Numer. Anal. 42 (2022), no. 2, 1598\u20131622.","DOI":"10.1093\/imanum\/drab002"},{"key":"2023033112515656061_j_cmam-2022-0033_ref_005","doi-asserted-by":"crossref","unstructured":"A. V. Balakrishnan,\nFractional powers of closed operators and the semigroups generated by them,\nPacific J. Math. 10 (1960), 419\u2013437.","DOI":"10.2140\/pjm.1960.10.419"},{"key":"2023033112515656061_j_cmam-2022-0033_ref_006","doi-asserted-by":"crossref","unstructured":"W. Barrett,\nConvergence properties of Gaussian quadrature formulae,\nComput. J. 3 (1960\/61), 272\u2013277.","DOI":"10.1093\/comjnl\/3.4.272"},{"key":"2023033112515656061_j_cmam-2022-0033_ref_007","doi-asserted-by":"crossref","unstructured":"A. Bonito, W. Lei and J. E. Pasciak,\nOn sinc quadrature approximations of fractional powers of regularly accretive operators,\nJ. Numer. 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Palencia,\nThe numerical range is a \n                  \n                     \n                        \n                           (\n                           \n                              1\n                              +\n                              \n                                 2\n                              \n                           \n                           )\n                        \n                     \n                     \n                     (1+\\sqrt{2})\n                  \n               -spectral set,\nSIAM J. Matrix Anal. Appl. 38 (2017), no. 2, 649\u2013655.","DOI":"10.1137\/17M1116672"},{"key":"2023033112515656061_j_cmam-2022-0033_ref_010","doi-asserted-by":"crossref","unstructured":"S. Harizanov, R. Lazarov and S. Margenov,\nA survey on numerical methods for spectral space-fractional diffusion problems,\nFract. Calc. Appl. 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