To cite dietr in publications please use:

dietr

  Borstein SR (2020). dietr: an R package for calculating fractional
  trophic levels from quantitative and qualitative diet data.
  Hydrobiologia 847, 4285-4294. 10.1007/s10750-020-04417-5.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {dietr: an R package for calculating fractional trophic levels from quantitative and qualitative diet data},
    author = {Samuel R. Borstein},
    journal = {Hydrobiologia},
    year = {2020},
    volume = {847},
    pages = {4285-4294},
    doi = {10.1007/s10750-020-04417-5},
  }