To cite TractoR (of which 'tractor.base' is part) in publications, please use:

Clayden JD, Maniega SM, Storkey AJ, King MD, Bastin ME, Clark CA (2011). “TractoR: Magnetic resonance imaging and tractography with R.” Journal of Statistical Software, 44(8), 1–18. https://www.jstatsoft.org/v44/i08/.

Corresponding BibTeX entry:

  @Article{,
    title = {{TractoR}: Magnetic resonance imaging and tractography
      with {R}},
    author = {Jonathan D. Clayden and Susana Mu\~{n}oz Maniega and Amos
      J. Storkey and Martin D. King and Mark E. Bastin and Chris A.
      Clark},
    journal = {Journal of Statistical Software},
    year = {2011},
    volume = {44},
    number = {8},
    pages = {1--18},
    url = {https://www.jstatsoft.org/v44/i08/},
  }