citation {utils}R Documentation

Citing R and R Packages in Publications


How to cite R and R packages in publications.


citation(package = "base", lib.loc = NULL, auto = NULL)

readCitationFile(file, meta = NULL)



a character string with the name of a single package. An error occurs if more than one package name is given.


a character vector with path names of R libraries, or the directory containing the source for package, or NULL. The default value of NULL corresponds to all libraries currently known. If the default is used, the loaded packages are searched before the libraries.


a logical indicating whether the default citation auto-generated from the package ‘DESCRIPTION’ metadata should be used or not, or NULL (default), indicating that a ‘CITATION’ file is used if it exists, or an object of class "packageDescription" with package metadata (see below).


a file name.


a list of package metadata as obtained by packageDescription, or NULL (the default).


character strings (which will be pasted).


The R core development team and the very active community of package authors have invested a lot of time and effort in creating R as it is today. Please give credit where credit is due and cite R and R packages when you use them for data analysis.

Execute function citation() for information on how to cite the base R system in publications. If the name of a non-base package is given, the function either returns the information contained in the ‘CITATION’ file of the package (using readCitationFile with meta equal to packageDescription(package, lib.loc)) or auto-generates citation information from the ‘DESCRIPTION’ file.

Packages can use an ‘⁠Authors@R⁠’ field in their ‘DESCRIPTION’ to provide (R code giving) a person object with a refined, machine-readable description of the package “authors” (in particular specifying their precise roles). Only those with an author role will be included in the auto-generated citation.

If the object returned by citation() contains only one reference, the associated print method shows both a text version and a BibTeX entry for it. If a package has more than one reference then only the text versions are shown. This threshold is controlled by options("citation.bibtex.max"). The BibTeX versions can also be obtained using function toBibtex() (see the examples below).

The ‘CITATION’ file of an R package should be placed in the ‘inst’ subdirectory of the package source. The file is an R source file and may contain arbitrary R commands including conditionals and computations. Function readCitationFile() is used by citation() to extract the information in ‘CITATION’ files. The file is source()ed by the R parser in a temporary environment and all resulting bibliographic objects (specifically, inheriting from "bibentry") are collected. These are typically produced by one or more bibentry() calls, optionally preceded by a citHeader() and followed by a citFooter() call. One can include an auto-generated package citation in the ‘CITATION’ file via citation(auto = meta).

readCitationFile makes use of the Encoding element (if any) of meta to determine the encoding of the file.


An object of class "citation", inheriting from class "bibentry"; see there, notably for the print and format methods.

citHeader and citFooter return an empty "bibentry" storing “outer” header/footer text for the package citation.

See Also



## the basic R reference

## extract the BibTeX entry from the return value
x <- citation()

## references for a package
citation("lattice", auto = TRUE)  # request the Manual-type reference

## a CITATION file with more than one bibentry:"CITATION", package="mgcv"))
cm <- citation("mgcv")
cm # header, text references, plus "reminder" about getting BibTeX
print(cm, bibtex = TRUE) # each showing its bibtex code

## a CITATION file including citation(auto = meta)"CITATION", package="nlme"))

[Package utils version 4.4.1 Index]