@article{JU21,
  author = {Jahn, Thomas and Ullrich, Tino},
  title = {{O}n the optimal constants in the two-sided {S}techkin inequalities},
  journal = {J. Approx. Theory},
  fjournal = {Journal of Approximation Theory},
  volume = {269},
  year = {2021},
  pages = {Article No. 105607, 25 pp.},
  doi = {10.1016/j.jat.2021.105607},
  url = {https://dx.doi.org/10.1016/j.jat.2021.105607},
}