To cite package 'nucleR' in publications use:

  Oscar Flores and Modesto Orozco (2011). nucleR: a package for
  non-parametric nucleosome positioning. Bioinformatics 2011,
  27:2149-215010.1093/bioinformatics/btr345

A BibTeX entry for LaTeX users is

  @Article{,
    title = {nucleR: a package for non-parametric nucleosome positioning},
    author = {Oscar Flores and Modesto Orozco},
    journal = {Bioinformatics},
    year = {2011},
    volume = {27},
    pages = {2149--2150},
    doi = {1093/bioinformatics/btr345},
  }