## Installation
```r
install.packages("rcrossref")
```
Or development version from GitHub
```r
devtools::install_github("ropensci/rcrossref")
```
```r
library("rcrossref")
```
## Usage
## Citation search
CrossRef's [DOI Content Negotiation](http://www.crosscite.org/cn/) service, where you can citations back in various formats, including `apa`
```r
cr_cn(dois = "10.1371/journal.pone.0112608", format = "text", style = "apa")
#> [1] "Wang, Q., & Taylor, J. E. (2014). Quantifying Human Mobility Perturbation and Resilience in Hurricane Sandy. PLoS ONE, 9(11), e112608. doi:10.1371/journal.pone.0112608"
```
There are a lot more styles. We include a dataset as a character vector within the package, accessible via the `get_styles()` function, e.g.,
```r
get_styles()[1:5]
#> [1] "academy-of-management-review"
#> [2] "acm-sig-proceedings-long-author-list"
#> [3] "acm-sig-proceedings"
#> [4] "acm-sigchi-proceedings-extended-abstract-format"
#> [5] "acm-sigchi-proceedings"
```
`bibtex`
```r
cat(cr_cn(dois = "10.1126/science.169.3946.635", format = "bibtex"))
#> @article{Frank_1970,
#> doi = {10.1126/science.169.3946.635},
#> url = {http://dx.doi.org/10.1126/science.169.3946.635},
#> year = 1970,
#> month = {aug},
#> publisher = {American Association for the Advancement of Science ({AAAS})},
#> volume = {169},
#> number = {3946},
#> pages = {635--641},
#> author = {H. S. Frank},
#> title = {The Structure of Ordinary Water: New data and interpretations are yielding new insights into this fascinating substance},
#> journal = {Science}
#> }
```
`bibentry`
```r
cr_cn(dois = "10.6084/m9.figshare.97218", format = "bibentry")
#> Boettiger; C (2012). "Regime shifts in ecology and evolution (PhD
#> Dissertation)." <URL: http://doi.org/10.6084/m9.figshare.97218>,
#> <URL: http://dx.doi.org/10.6084/m9.figshare.97218>.
```
## Citation count
Citation count, using OpenURL
```r
cr_citation_count(doi="10.1371/journal.pone.0042793")
#> [1] 8
```
## Search Crossref metadata API
There are two functions that use an older Crossre API: `cr_search()` and `cr_search_free()`. You can of course use them, but the newer Crossref API available through various functions (`cr_agency()`, `cr_fundref()`, `cr_journals()`, `cr_licenses()`, `cr_members()`, `cr_prefixes()`, and `cr_works()`) is more powerful and will recieve more support going forward. The following functions (of the newer set just mentioend) all use the [CrossRef API](https://github.com/CrossRef/rest-api-doc/blob/master/rest_api.md).
### Look up funder information
```r
cr_fundref(query="NSF")
#> $meta
#> total_results search_terms start_index items_per_page
#> 1 8 NSF 0 20
#>
#> $data
#> id location
#> 1 100003187 United States
#> 2 100008367 Denmark
#> 3 501100004190 Norway
#> 4 100000179 United States
#> 5 100006445 United States
#> 6 501100000930 Australia
#> 7 100000001 United States
#> 8 501100001809 China
#> name
#> 1 National Sleep Foundation
#> 2 Statens Naturvidenskabelige Forskningsrad
#> 3 Norsk Sykepleierforbund
#> 4 NSF Office of the Director
#> 5 Center for Hierarchical Manufacturing, National Science Foundation
#> 6 National Stroke Foundation
#> 7 National Science Foundation
#> 8 National Natural Science Foundation of China
#> alt.names
#> 1 NSF
#> 2 SNF, Danish National Science Foundation, Danish NSF
#> 3 NSF, Norwegian Nurses Organisation
#> 4 OD
#> 5 CHM, NSF, University of Massachusetts NSF Center for Hierarchical Manufacturing, Center for Hierarchical Manufacturing
#> 6 NSF
#> 7 NSF
#> 8 Natural Science Foundation of China, National Science Foundation of China, NSFC
#> uri
#> 1 http://dx.doi.org/10.13039/100003187
#> 2 http://dx.doi.org/10.13039/100008367
#> 3 http://dx.doi.org/10.13039/501100004190
#> 4 http://dx.doi.org/10.13039/100000179
#> 5 http://dx.doi.org/10.13039/100006445
#> 6 http://dx.doi.org/10.13039/501100000930
#> 7 http://dx.doi.org/10.13039/100000001
#> 8 http://dx.doi.org/10.13039/501100001809
#> tokens
#> 1 national, sleep, foundation, nsf
#> 2 statens, naturvidenskabelige, forskningsrad, snf, danish, national, science, foundation, danish, nsf
#> 3 norsk, sykepleierforbund, nsf, norwegian, nurses, organisation
#> 4 nsf, office, of, the, director, od
#> 5 center, for, hierarchical, manufacturing, national, science, foundation, chm, nsf, university, of, massachusetts, nsf, center, for, hierarchical, manufacturing, center, for, hierarchical, manufacturing
#> 6 national, stroke, foundation, nsf
#> 7 national, science, foundation, nsf
#> 8 national, natural, science, foundation, of, china, natural, science, foundation, of, china, national, science, foundation, of, china, nsfc
```
### Check the DOI minting agency
```r
cr_agency(dois = '10.13039/100000001')
#> $DOI
#> [1] "10.13039/100000001"
#>
#> $agency
#> $agency$id
#> [1] "crossref"
#>
#> $agency$label
#> [1] "CrossRef"
```
### Search works (i.e., articles, books, etc.)
```r
cr_works(filter=c(has_orcid=TRUE, from_pub_date='2004-04-04'), limit=1)
#> $meta
#> total_results search_terms start_index items_per_page
#> 1 296797 NA 0 1
#>
#> $data
#> alternative.id container.title created deposited
#> 1 2015-11-11 2015-11-11
#> DOI funder indexed ISBN ISSN issued link
#> 1 10.19138/ejaz.1437.1 NULL 2015-11-14 2012-07-13 NULL
#> member
#> 1 http://id.crossref.org/member/8212
#> prefix
#> 1 http://id.crossref.org/prefix/10.19138
#> publisher reference.count score source
#> 1 Academic Journal, Al-Azhar University 0 1 CrossRef
#> subject title type
#> 1 الإعجاز في قوله تعالى "والمرسلات عرفا" report
#> URL assertion
#> 1 http://dx.doi.org/10.19138/ejaz.1437.1 NULL
#> author
#> 1 معوض, رامي, http://orcid.org/0000-0003-4211-3903
#>
#> $facets
#> NULL
```
### Search journals
```r
cr_journals(issn=c('1803-2427','2326-4225'))
#> alternative.id container.title created deposited funder indexed ISBN
#> 1 NULL
#> 2 NULL
#> ISSN issued link publisher subject
#> 1 1803-2427 NULL De Gruyter Open Sp. z o.o.
#> 2 2326-4225 NULL American Scientific Publishers
#> title assertion author
#> 1 Journal of Landscape Ecology NULL NULL
#> 2 Journal of Nutritional Ecology and Food Research NULL NULL
```
### Search license information
```r
cr_licenses(query = 'elsevier')
#> $meta
#> total_results search_terms start_index items_per_page
#> 1 12 elsevier 0 20
#>
#> $data
#> URL
#> 1 http://creativecommons.org/licenses/by-nc-nd/3.0/
#> 2 http://creativecommons.org/licenses/by-nc-nd/4.0/
#> 3 http://creativecommons.org/licenses/by/3.0/
#> 4 http://creativecommons.org/licenses/by/4.0/
#> 5 http://doi.wiley.com/10.1002/tdm_license_1
#> 6 http://onlinelibrary.wiley.com/termsAndConditions
#> 7 http://www.acm.org/publications/policies/copyright_policy#Background
#> 8 http://www.elsevier.com/open-access/userlicense/1.0/
#> 9 http://www.elsevier.com/tdm/userlicense/1.0/
#> 10 http://www.springer.com/tdm
#> 11 © 2007 Elsevier Masson SAS. All rights reserved. The patient figure in Figure 6, part A is reproduced from Ferrero et al., (2007), European Journal of Medical Genetics with permission.
#> 12 © 2012, Elsevier Inc., All Rights Reserved. Figure 8, part (B) (images of HVCX dendrites from LMAN intact bird) is reprinted with permission from Figure 1B in Tschida and Mooney, 2012.
#> work.count
#> 1 12
#> 2 3
#> 3 2
#> 4 1
#> 5 2266
#> 6 214
#> 7 3
#> 8 3
#> 9 1198
#> 10 9
#> 11 1
#> 12 1
```
### Search based on DOI prefixes
```r
cr_prefixes(prefixes=c('10.1016','10.1371','10.1023','10.4176','10.1093'))
#> $meta
#> NULL
#>
#> $data
#> member name
#> 1 http://id.crossref.org/member/78 Elsevier BV
#> 2 http://id.crossref.org/member/340 Public Library of Science (PLoS)
#> 3 http://id.crossref.org/member/297 Springer Science + Business Media
#> 4 http://id.crossref.org/member/1989 Co-Action Publishing
#> 5 http://id.crossref.org/member/286 Oxford University Press (OUP)
#> prefix
#> 1 http://id.crossref.org/prefix/10.1016
#> 2 http://id.crossref.org/prefix/10.1371
#> 3 http://id.crossref.org/prefix/10.1023
#> 4 http://id.crossref.org/prefix/10.4176
#> 5 http://id.crossref.org/prefix/10.1093
#>
#> $facets
#> list()
```
### Search CrossRef members
```r
cr_members(query='ecology', limit = 5)
#> $meta
#> total_results search_terms start_index items_per_page
#> 1 17 ecology 0 5
#>
#> $data
#> id primary_name
#> 1 7052 Chinese Journal of Plant Ecology
#> 2 6933 Knowledge Ecology International
#> 3 7278 Korean Society of Ecology and Infrastructure Engineering
#> 4 7745 Institute of Applied Ecology
#> 5 336 Japanese Society of Microbial Ecology
#> location
#> 1 Room 216 15 Fuxing Road Beijing 100038 China
#> 2 1621 Connecticut Avenue NW Suite 500 Washington DC 20009 United States
#> 3 245 Daehangno Yusong Yusong Daejeon 305-806 South Korea
#> 4 Bld. 1, 46 Myasnitskaya Str. Moscow 101000 Russian Federation
#> 5 5-3 Yonbancho Chiyoda-ku Tokyo 102-0081 Japan
#> last_status_check_time backfile.dois current.dois total.dois prefixes
#> 1 2016-05-02 644 141 785 10.17521
#> 2 2016-05-02 0 0 0 10.17534
#> 3 2016-05-02 6 56 62 10.17820
#> 4 2016-05-02 0 527 527 10.18470
#> 5 2016-05-02 889 66 955 10.1264
#> coverge.funders.backfile coverge.licenses.backfile
#> 1 0 0
#> 2 0 0
#> 3 0 0
#> 4 0 0
#> 5 0 0
#> coverge.funders.current coverge.resource.links.backfile
#> 1 0 0
#> 2 0 0
#> 3 0 0
#> 4 0 0
#> 5 0 0
#> coverge.orcids.backfile coverge.update.policies.current
#> 1 0 0
#> 2 0 0
#> 3 0 0
#> 4 0 0
#> 5 0 0
#> coverge.orcids.current coverge.references.backfile
#> 1 0 0.00155279505997896
#> 2 0 0
#> 3 0 1
#> 4 0 0
#> 5 0 0.676040470600128
#> coverge.award.numbers.backfile coverge.update.policies.backfile
#> 1 0 0
#> 2 0 0
#> 3 0 0
#> 4 0 0
#> 5 0 0
#> coverge.licenses.current coverge.award.numbers.current
#> 1 0 0
#> 2 0 0
#> 3 0 0
#> 4 0 0
#> 5 0 0
#> coverge.resource.links.current coverge.references.current
#> 1 0 0
#> 2 0 0
#> 3 0 0.839285731315613
#> 4 0.905123353004456 0
#> 5 0 0.727272748947144
#> flags.deposits.orcids.current flags.deposits
#> 1 FALSE TRUE
#> 2 FALSE FALSE
#> 3 FALSE TRUE
#> 4 FALSE TRUE
#> 5 FALSE TRUE
#> flags.deposits.update.policies.backfile
#> 1 FALSE
#> 2 FALSE
#> 3 FALSE
#> 4 FALSE
#> 5 FALSE
#> flags.deposits.award.numbers.current
#> 1 FALSE
#> 2 FALSE
#> 3 FALSE
#> 4 FALSE
#> 5 FALSE
#> flags.deposits.resource.links.current flags.deposits.articles
#> 1 FALSE TRUE
#> 2 FALSE FALSE
#> 3 FALSE TRUE
#> 4 TRUE TRUE
#> 5 FALSE TRUE
#> flags.deposits.funders.current flags.deposits.references.backfile
#> 1 FALSE TRUE
#> 2 FALSE FALSE
#> 3 FALSE TRUE
#> 4 FALSE FALSE
#> 5 FALSE TRUE
#> flags.deposits.licenses.backfile flags.deposits.award.numbers.backfile
#> 1 FALSE FALSE
#> 2 FALSE FALSE
#> 3 FALSE FALSE
#> 4 FALSE FALSE
#> 5 FALSE FALSE
#> flags.deposits.references.current flags.deposits.resource.links.backfile
#> 1 FALSE FALSE
#> 2 FALSE FALSE
#> 3 TRUE FALSE
#> 4 FALSE FALSE
#> 5 TRUE FALSE
#> flags.deposits.orcids.backfile flags.deposits.funders.backfile
#> 1 FALSE FALSE
#> 2 FALSE FALSE
#> 3 FALSE FALSE
#> 4 FALSE FALSE
#> 5 FALSE FALSE
#> flags.deposits.update.policies.current flags.deposits.licenses.current
#> 1 FALSE FALSE
#> 2 FALSE FALSE
#> 3 FALSE FALSE
#> 4 FALSE FALSE
#> 5 FALSE FALSE
#> names
#> 1 Chinese Journal of Plant Ecology
#> 2 Knowledge Ecology International
#> 3 Korean Society of Ecology and Infrastructure Engineering
#> 4 Institute of Applied Ecology
#> 5 Japanese Society of Microbial Ecology
#> tokens
#> 1 chinese, journal, of, plant, ecology
#> 2 knowledge, ecology, international
#> 3 korean, society, of, ecology, and, infrastructure, engineering
#> 4 institute, of, applied, ecology
#> 5 japanese, society, of, microbial, ecology
#>
#> $facets
#> NULL
```
### Get N random DOIs
`cr_r()` uses the function `cr_works()` internally.
```r
cr_r()
#> [1] "10.1103/physrevb.59.3086" "10.3807/josk.2015.19.1.095"
#> [3] "10.1159/000406186" "10.3775/jie.18.797"
#> [5] "10.1109/pgec.1967.264707" "10.1177/1354068806064733"
#> [7] "10.1007/s10862-007-9070-0" "10.1016/0893-6080(94)90013-2"
#> [9] "10.1787/9789264007550-sum-sv" "10.1111/j.1399-302x.2007.00354.x"
```
You can pass in the number of DOIs you want back (default is 10)
```r
cr_r(2)
#> [1] "10.2134/jeq2007.0203" "10.1007/bf00404592"
```
### The older functions and API
Search by author
```r
cr_search(query = c("renear", "palmer"), rows = 3, sort = "year")[1:2,-6]
#> doi score
#> 1 http://dx.doi.org/10.1007/978-3-658-12433-5 0.7289054
#> 2 http://dx.doi.org/10.13110/merrpalmquar1982.62.1.fm 0.6872187
#> normalizedScore title
#> 1 22 Berufsbezogene Kreativitätsdiagnostik
#> 2 20 Front Matter
#> fullCitation
#> 1 Carolin Palmer, 2016, 'Berufsbezogene Kreativitätsdiagnostik'
#> 2 2016, 'Front Matter', Merrill-Palmer Quarterly, vol. 62, no. 1, p. i
#> year
#> 1 2016
#> 2 2016
```
Search by DOI
```r
cr_search(doi = "10.1890/10-0340.1")[,-6]
#> doi score normalizedScore
#> 1 http://dx.doi.org/10.1890/10-0340.1 17.97163 100
#> title
#> 1 The arcsine is asinine: the analysis of proportions in ecology
#> fullCitation
#> 1 David I. Warton, Francis K. C. Hui, 2011, 'The arcsine is asinine: the analysis of proportions in ecology', Ecology, vol. 92, no. 1, pp. 3-10
#> year
#> 1 2011
```
Free search
```r
queries <- c("Piwowar sharing data PLOS one", "Priem Scientometrics 2.0 social web",
"William Gunn A Crosstalk Between Myeloma Cells",
"karthik ram Metapopulation dynamics override local limits")
cr_search_free(queries)[,-4]
#> text match
#> 1 Piwowar sharing data PLOS one TRUE
#> 2 Priem Scientometrics 2.0 social web TRUE
#> 3 William Gunn A Crosstalk Between Myeloma Cells TRUE
#> 4 karthik ram Metapopulation dynamics override local limits TRUE
#> doi score
#> 1 http://dx.doi.org/10.1371/journal.pone.0000308 3.247673
#> 2 http://dx.doi.org/10.5210/fm.v15i7.2874 3.595765
#> 3 http://dx.doi.org/10.1634/stemcells.2005-0220 2.813690
#> 4 http://dx.doi.org/10.1890/08-0228.1 3.950688
```
## Citing
To cite `rcrossref` in publications use:
> Scott Chamberlain, Carl Boettiger, Ted Hart, and Karthik Ram (2014). rcrossref:
R Client for Various CrossRef APIs. R package version 0.3.0
https://github.com/ropensci/rcrossref
## License and bugs
* License: [MIT](http://opensource.org/licenses/MIT)
* Report bugs at [our Github repo for rcrossref](https://github.com/ropensci/rcrossref/issues?state=open)
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