To cite ptm in publications use:

Aledo J (2021). “ptm: an R package for the study of methionine sulfoxidation and other posttranslational modifications.” Bioinformatics, 37(21), 3979–3980. https://academic.oup.com/bioinformatics/article-abstract/37/21/3979/6272576.

Corresponding BibTeX entry:

  @Article{,
    title = {{ptm}: an R package for the study of methionine
      sulfoxidation and other posttranslational modifications},
    author = {Juan Carlos Aledo},
    journal = {Bioinformatics},
    year = {2021},
    volume = {37},
    number = {21},
    pages = {3979--3980},
    url =
      {https://academic.oup.com/bioinformatics/article-abstract/37/21/3979/6272576},
  }