If it were me, I’d link maybe two articles with a brief explanation in the additional info.
If a schools has a place to upload something, then maybe pdf 3-5 pages and that’s it. You don’t want too much.
It will depend on the school - some will allow a submission like this.
If you put in the additional info section but for some want to submit differently where allowed, make sure you delete the additional info section b4 submitting it to that school so you are not duplicating.
Good luck