To cite choplump in publications use:

Follmann D, Fay MP, Proschan M (2009). “Chop-Lump Tests for Vaccine Trials.” Biometrics, 65, 885–893.

Corresponding BibTeX entry:

  @Article{,
    title = {Chop-Lump Tests for Vaccine Trials},
    author = {Dean Follmann and Michael P. Fay and Michael Proschan},
    journal = {Biometrics},
    year = {2009},
    volume = {65},
    pages = {885--893},
  }