To cite the 'mnlfa' package in publications use:

Robitzsch, A. (2019). mnlfa: Moderated nonlinear factor analysis. R package version 0.1-53. https://CRAN.R-project.org/package=mnlfa

Corresponding BibTeX entry:

  @Manual{,
    title = {mnlfa: Moderated nonlinear factor analysis},
    author = {Alexander Robitzsch},
    year = {2019},
    note = {R package version 0.1-53},
    url = {https://CRAN.R-project.org/package=mnlfa},
  }