# 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)

* [Basic](https://adidas-itlearning.udemy.com/course/onboarding-16-api-development-management/)
* [Deep Dive](https://adidas-itlearning.udemy.com/course/onboarding-21-api-development-management/)
* [OpenAPI](https://adidas-itlearning.udemy.com/course/openapi-beginner-to-guru/learn/)