To cite sylly.en in publications use:

Michalke, M. (2018). sylly.en: Language Support for 'sylly' Package: English (Version 0.1-3). Available from http://reaktanz.de/?c=hacking&s=koRpus

Corresponding BibTeX entry:

  @Manual{,
    title = {sylly.en: Language Support for 'sylly' Package: English},
    author = {Meik Michalke},
    year = {2018},
    note = {(Version 0.1-3)},
    url = {http://reaktanz.de/?c=hacking&s=koRpus},
  }