Reference:
  Author: Arne Henningsen and Ott Toomet
  Title: "maxLik: A package for maximum likelihood estimation in R."
  Journal: Computational Statistics
  Year: 2011
  Volume: 26
  Number: 3
  Pages: 443-458
  DOI: 10.1007/s00180-010-0217-1
  URL: http://link.springer.com/article/10.1007%2Fs00180-010-0217-1
