To cite package 'meta' in publications use:

Schwarzer G (2007). “meta: An R package for meta-analysis.” R News, 7(3), 40–45.

URL https://cran.r-project.org/doc/Rnews/Rnews_2007-3.pdf

Corresponding BibTeX entry:

  @Article{,
    title = {meta: {A}n {R} package for meta-analysis},
    author = {Guido Schwarzer},
    journal = {R News},
    year = {2007},
    volume = {7},
    number = {3},
    pages = {40--45},
  }