@unpublished{arxiv,
author = {J. Gedicke, S. Geevers, and I. Perugia},
title = {An equilibrated a posteriori error estimator for arbitrary-order {N}édélec elements for magnetostatic problems},
note = {arXiv preprint 1909.01853},
year = {2019},
url = {https://arxiv.org/abs/1909.01853},
}