Reference to other posts

I would like to include a link to another post inside my new post. Is there a better way than copying the URL ?
The reason I want an alternative is that post URLs change depending on the post title, so if I decide to change a title, all post links will need to be changed.

Is this possible ? post urls should stay the same regardless if you change the title. The only way to change the url or slug for a post that has already been published, is to edit the post and change the slug value in the metadata.