[1] [CITE@en[rest-api-doc/rest_api.md at master · CrossRef/rest-api-doc]]
([TIME[2017-04-20 17:58:37 +09:00]])
<https://github.com/CrossRef/rest-api-doc/blob/master/rest_api.md>

[FIG(quote)[
[FIGCAPTION[
[2] [CITE@en[rest-api-doc/rest_api.md at master · CrossRef/rest-api-doc]]
([TIME[2017-04-20 18:06:31 +09:00]])
<https://github.com/CrossRef/rest-api-doc/blob/master/rest_api.md>
]FIGCAPTION]

> If you need to tie your implementation to a specific major version of the API, you can do so by using content-negotiation and specifying the version of the API in the ACCEPT header as follows:
>  application/vnd.crossref-api-message+json; version=1.0

]FIG]