1
WebAIM's contrast ratio checker
https://webaim.org/resources/contrastchecker/
2
Quote from WebAIM's introduction page on accessibility guidelines
https://webaim.org/intro/#types
3
Quote from the W3C Web Accessibility Initiative on the use of ARIA tags
https://www.w3.org/WAI/standards-guidelines/aria/
4
Quote from the documentation of Sphinx, about their docstring syntax
https://sphinx-rtd-tutorial.readthedocs.io/en/latest/docstrings.html
5
WebAIM's introduction article that contains the list of reccommended accessibility requirements
https://webaim.org/intro/