To cite cquad in publications use:

Bartolucci F, Pigini C (2017). “cquad: An R and Stata Package for Conditional Maximum Likelihood Estimation of Dynamic Binary Panel Data Models.” Journal of Statistical Software, 78(7), 1–26. doi:10.18637/jss.v078.i07.

Corresponding BibTeX entry:

  @Article{,
    title = {{cquad}: An {R} and {Stata} Package for Conditional
      Maximum Likelihood Estimation of Dynamic Binary Panel Data
      Models},
    author = {Francesco Bartolucci and Claudia Pigini},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {78},
    number = {7},
    pages = {1--26},
    doi = {10.18637/jss.v078.i07},
  }