diff --git a/src/content/classnotes/html/introduction/index.mdx b/src/content/classnotes/html/introduction/index.mdx
index e865c5c..c04497f 100644
--- a/src/content/classnotes/html/introduction/index.mdx
+++ b/src/content/classnotes/html/introduction/index.mdx
@@ -62,6 +62,7 @@ Referências:
 - Elementos
   - [HTML Reference | MDN](https://developer.mozilla.org/en-US/docs/Web/HTML/Element)
   - [Elements | WHATWG](https://html.spec.whatwg.org/multipage/indices.html#elements-3)
+  - [A simple guide to HTML head elements](https://htmlhead.dev/)
 - Categorias
   - [Content categories | MDN](https://developer.mozilla.org/en-US/docs/Web/HTML/Content_categories)
   - [Element content categories | WHATWG](https://html.spec.whatwg.org/multipage/indices.html#element-content-categories)