To cite NetworkToolbox in publications use:

  Christensen, A. P. (2018). NetworkToolbox: Methods and measures for
  brain, cognitive, and psychometric network analysis in R. The R
  Journal, 10, 422-439. https://doi.org/10.32614/RJ-2018-065

A BibTeX entry for LaTeX users is

  @Article{NetworkToolbox,
    title = {{NetworkToolbox}: Methods and measures for brain, cognitive, and psychometric network analysis in {R}},
    author = {Christensen, Alexander},
    journal = {The R Journal},
    pages = {422--439},
    year = {2018},
    doi = {10.32614/RJ-2018-065},
  }