To cite package 'metap' in publications use:

Michael Dewey (2018). metap: meta-analysis of significance values. R package version 0.9.

Corresponding BibTeX entry:

  @Manual{,
    title = {{metap}: meta-analysis of significance values},
    author = {Michael Dewey},
    year = {2018},
    note = {R package version 0.9},
  }