[Tex/LaTex] Natbib: How to show names of all authors for pieces with 3 or more authors the first time a piece is cited, and use “et al.” for subsequent citations

authoryearcitingnatbib

I am submitting a paper to a journal that requires the following citation format:

  • If a work has two authors, give both names every time you cite it.
  • For three through six authors, give all names the first time, then
    use “et al.” in citations.

Example:

First citation: (Foster, Whittington, Tucker, Horner, Hubbard, & Grimm, 2000).

Subsequent citation: (Foster et al., 2000).

How can I achieve this in natbib, for both \citet{} and \citep{}?

Best Answer

Load the natbib package with the option longnamesfirst.

From page 8 of the package's user guide:

Some publishers require that the first citation of any given reference be given with the full author list, but that all subsequent ones with the abbreviated list. Include the option longnamesfirst to enable this for natbib.

Just to be clear: The longnamesfirst option will show all authors' names even if a piece has more than 6 authors. You didn't specify what should be done in such cases; if, in fact, you're supposed to be employing the APA6 truncation method for such pieces, you should not use the natbib citation management package. In its place, you should probably employ the apacite package (with the option natbibapa, if you wish to enable the \citet and \citep macros) and the apacite bibliography style.


Addendum, Dec. 2021: The suggestion made in the preceding paragraph -- viz., to employ the apacite package and apacite bib style -- was fine back in January 2016. In the meantime, the APA has issued another (seventh) set of formatting guidelines for citation call-outs and bibliographies. If you need to adhere to current APA formatting guidelines, you should prepare to switch from apacite and BibTeX to biblatex (with option style=apa) and biber.