To cite whitebox in publications use:

Lindsay JB (2016). “Whitebox GAT: A case study in geomorphometric analysis.” Computers & Geosciences, 95, 75-84. http://dx.doi.org/10.1016/j.cageo.2016.07.003.

Corresponding BibTeX entry:

  @Article{,
    title = {Whitebox GAT: A case study in geomorphometric analysis.},
    author = {J. B. Lindsay},
    journal = {Computers & Geosciences},
    year = {2016},
    volume = {95},
    pages = {75-84},
    url = {http://dx.doi.org/10.1016/j.cageo.2016.07.003},
  }