To cite the nlreg package in publications use:

  Alessandra R. B (2005). “hoa: An R package bundle for higher order
  likelihood inference.” _The R Journal_, *5/1 May*, 20-27. ISSN
  609-3631,
  <https://journal.r-project.org/articles/RN-2005-004/RN-2005-004.pdf>.

A BibTeX entry for LaTeX users is

  @Article{Rnewspaper,
    author = {Brazzale {Alessandra R.}},
    title = {{hoa}: {An} {R} package bundle for higher order likelihood inference},
    journal = {The R Journal},
    volume = {5/1 {May}},
    year = {2005},
    pages = {20--27},
    note = {{ISSN} 609-3631},
    url = {https://journal.r-project.org/articles/RN-2005-004/RN-2005-004.pdf},
  }

Examples of applications, and generally of the use of likelihood
asymptotics, are given in:

Brazzale, A.R., Davison, A.C. and Reid, N. (2007).  Applied
Asymptotics: Case Studies in Small-Sample Statistics.  Cambridge
University Press, Cambridge.