Simple tutorial that will teach you to configure your system to automatically install security updates.

Nice blog (in appearance, contents and implementation). See https://archive.casouri.cat/note/2018/blog-in-org-mode-revisited/index.html for an update.
An interesting idea for entering mathematical symbols is presented on https://archive.casouri.cat/note/2020/insert-math-symbol-in-emacs/index.html