@article{DiUl12,
  author = {{D}ung, {D}inh and {U}llrich, Tino},
  title = {{N}-widths and $\varepsilon$-dimensions for
		  high-dimensional approximations},
  year = {2013},
  pages = {965--1003},
  volume = {13},
  journal = {Found. Comput. Math.},
  annote = {journal,group},
  pdf = {https://www.tu-chemnitz.de/mathematik/ang_analysis/Publications/DuUl12.pdf}
}