To cite poLCA in publications use:

Linzer DA, Lewis JB (2011). “poLCA: An R Package for Polytomous Variable Latent Class Analysis.” Journal of Statistical Software, 42(10), 1–29. https://www.jstatsoft.org/v42/i10/.

Corresponding BibTeX entry:

  @Article{,
    title = {{poLCA}: An {R} Package for Polytomous Variable Latent
      Class Analysis},
    author = {Drew A. Linzer and Jeffrey B. Lewis},
    journal = {Journal of Statistical Software},
    year = {2011},
    volume = {42},
    number = {10},
    pages = {1--29},
    url = {https://www.jstatsoft.org/v42/i10/},
  }