please refer to the M-M.E.S.S. toolbox by its acronym and the version number. The core copyright holders are Jens Saak, Martin Köhler and Peter Benner. They have to be given as the authors in a citation. The project is frequently updated on Zenodo and every stable release will receive a DOI for proper citation there. The DOI for this version and a sample BibTeX entry can be found below.
The DOI for version 3.0 is 10.5281/zenodo.7701424
@Misc{SaaKB21-mmess-3.0,
author = {Saak, J. and K\"{o}hler, M. and Benner, P.},
title = {{M-M.E.S.S.}-3.0 -- The Matrix Equations Sparse Solvers
library},
month = aug,
year = 2023,
note = {see also:\url{https://www.mpi-magdeburg.mpg.de/projects/mess}},
doi = {10.5281/zenodo.7701424},
key = {MMESS}
}