Itai, Uri, and Nir Sharon. 2013. “Subdivision Schemes for Positive Definite Matrices”. Foundations of Computational Mathematics 13 (3). Springer: 347–369. Reference Link
Sharon, Nir, and Uri Itai. 2013. “Approximation Schemes for Functions of Positive-Definite Matrix Values”. IMA Journal of Numerical Analysis 33 (4). Oxford University Press: 1436–1468. Reference Link
Dyn, Nira, Uri Itai, and Nir Sharon. 2014. “Approximation Operators for Matrix-Valued Functions Based on Matrix Decompositions.” Reference Link