To cite cernn in publications, please use:

Eric C. Chi and Kenneth Lange, Stable estimation of a covariance matrix guided by nuclear norm penalties, Computational Statistics and Data Analysis, 80:117-128, 2014.

Corresponding BibTeX entry:

  @Article{,
    title = {Stable estimation of a covariance matrix guided by nuclear
      norm penalties},
    author = {Eric C. Chi and Kenneth Lange},
    year = {2014},
    volume = {80},
    pages = {117--128},
    doi = {http://dx.doi.org/10.1016/j.csda.2014.06.018},
    issn = {0167-9473},
    journal = {Computational Statistics and Data Analysis},
    url =
      {http://www.sciencedirect.com/science/article/pii/S0167947314001893},
  }