To cite package ‘xreg2’ in publications use:

  Rand K (2026). _xreg2: Flexible Maximum Likelihood Regression with
  Gradient-Based Optimisation_. R package version 0.1.4,
  <https://github.com/mathsinhealth/xreg2>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {xreg2: Flexible Maximum Likelihood Regression with Gradient-Based
Optimisation},
    author = {Kim Rand},
    year = {2026},
    note = {R package version 0.1.4},
    url = {https://github.com/mathsinhealth/xreg2},
  }