Referat oparty jest na pracach:
Paul F. X. Müller, Markus Passenbrunner, Almost everywhere Convergence of Spline Sequences, https://arxiv.org/abs/1711.01859, (to appear in Israel J. Math.)
oraz
Markus Passenbrunner, Spline Characterizations of the Radon-Nikodým property, https://arxiv.org/abs/1807.01861, DOI: https://doi.org/10.1090/proc/14711.