To cite package 'UWHAM' in publications use:

Tan, Z. and Gallicchio, E. (2012). UWHAM: Unbinned weighted histogram analysis method. R package version 1.0.

Corresponding BibTeX entry:

  @Manual{,
    title = {UWHAM: Unbinned weighted histogram analysis method},
    author = {Zhiqiang Tan and Emilio Gallicchio},
    year = {2012},
    note = {R package version 1.0},
  }