Hey Pablo,

> One of the not irrelevant tasks for me is finding examples of XML code.

To clarify, XHTML documents *are* XML documents. XHTML happens to use a
standardized set of XML element and attribute names. All XHTML examples are
also XML examples.

> But my worries came from having to sanitize HTML sources (which aren’t

That was discussed in the blog post: finding a source of well-formed XHTML
documents. There are a number of tools to sanitize HTML, as mentioned in
the thread. KeenWrite uses the Java-based JSoup library https://jsoup.org/
to sanitize HTML and then create an XHTML version.

All the best!