To cite ggtern in publications use:

Hamilton NE, Ferry M (2018). “ggtern: Ternary Diagrams Using ggplot2.” Journal of Statistical Software, Code Snippets, 87(3), 1–17. doi:10.18637/jss.v087.c03.

Corresponding BibTeX entry:

  @Article{,
    title = {{ggtern}: Ternary Diagrams Using {ggplot2}},
    author = {Nicholas E. Hamilton and Michael Ferry},
    journal = {Journal of Statistical Software, Code Snippets},
    year = {2018},
    volume = {87},
    number = {3},
    pages = {1--17},
    doi = {10.18637/jss.v087.c03},
  }