To cite tabula in publications use:

Frerebeau N (2019). “tabula: An R Package for Analysis, Seriation, and Visualization of Archaeological Count Data.” Journal of Open Source Software, 4(44). doi: 10.21105/joss.01821.

Corresponding BibTeX entry:

  @Article{,
    title = {{tabula}: An R Package for Analysis, Seriation, and
      Visualization of Archaeological Count Data},
    author = {Nicolas Frerebeau},
    year = {2019},
    journal = {Journal of Open Source Software},
    volume = {4},
    number = {44},
    page = {1821},
    doi = {10.21105/joss.01821},
  }