When using this data, please cite the original publication:

Additionally, you should cite the record:

@misc{hepdata.91127, author = "{ATLAS Collaboration}", title = "{Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in $\sqrt{s}$ = 13 TeV $pp$ collisions with the ATLAS detector}", howpublished = "{HEPData (collection)}", year = 2020, note = "\url{https://doi.org/10.17182/hepdata.91127}" }

or, if you prefer, a specific version of the record:

@misc{hepdata.91127.v2, author = "{ATLAS Collaboration}", title = "{Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in $\sqrt{s}$ = 13 TeV $pp$ collisions with the ATLAS detector (Version 2)}", howpublished = "{HEPData (collection)}", year = 2020, note = "\url{https://doi.org/10.17182/hepdata.91127.v2}" }

You can also cite this resource directly.

@misc{hepdata.91127.v2/r3, author = "{ATLAS Collaboration}", title = "{``likelihoods_ANA-SUSY-2018-06_3L-RJ-mimic.tar.gz'' of ``Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in $\sqrt{s}$ = 13 TeV $pp$ collisions with the ATLAS detector'' (Version 2)}", howpublished = "{HEPData (other)}", year = 2020, note = "\url{https://doi.org/10.17182/hepdata.91127.v2/r3}" }