To cite the metaMS package publications use:

  R. Wehrens, G. Weingart and F. Mattivi, metaMS: An open-source
  pipeline for GC-MS-based untargeted metabolomics J. Chrom. B (2014),
  v966, 109-116.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {metaMS: An open-source pipeline for GC-MS-based untargeted metabolomics},
    author = {R. Wehrens and G. Weingart and F. Mattivi},
    year = {2014},
    journal = {J. Chrom. B},
    volume = {966},
    pages = {109-116},
  }