To cite ushr, please use:

  S. E. Morris, L. Dziobek-Garrett, A. J. Yates, in collaboration with
  the EPIICAL Consortium (2020). ushr: Understanding suppression of HIV
  in R. BMC Bioinformatics 21(52).

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Sinead E. Morris and Luise Dziobek-Garrett and Andrew J. Yates},
    title = {ushr: Understanding suppression of HIV in R},
    year = {2020},
    journal = {BMC Bioinformatics},
    volume = {21},
    number = {52},
    doi = {10.1186/s12859-020-3389-x},
  }