To cite calendar-based graphics in publications, please use:

  Wang, E, D Cook, and RJ Hyndman (2020). Calendar-based graphics for
  visualizing people's daily schedules, Journal of Computational and
  Graphical Statistics, 29:3, 490-502,
  doi:10.1080/10618600.2020.1715226.

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Earo Wang and Dianne Cook and Rob J Hyndman},
    title = {Calendar-based graphics for visualizing people's daily schedules},
    journal = {Journal of Computational and Graphical Statistics},
    volume = {29},
    number = {3},
    pages = {490-502},
    year = {2020},
    publisher = {Taylor & Francis},
    doi = {10.1080/10618600.2020.1715226},
    url = {https://doi.org/10.1080/10618600.2020.1715226},
  }