# Further References

* [Product tokens](https://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-16#section-6.3)
* [Deprecating "X-"](https://tools.ietf.org/html/rfc6648)
* [Collection of standards and specifications for HTTP/REST APIs](http://standards.rest)
* [Official list of HTTP Message Headers](https://www.iana.org/assignments/message-headers/message-headers.xhtml)

## Tools documentation

* [SwaggerHub Documentation](https://app.swaggerhub.com/help/index)

## Learning Path (adidas-Udemy)

* [Get Started with Kong Multi-Cluster](https://adidas-itlearning.udemy.com/course/get-started-kong/learn/lecture/43319098#search)