Hi, I sent you a rather gentle warning on the matter. You removed a link to an article from a highly known and reputable magazine and replaced it with a link to a video page. What would have been more appropriate is to add that link in the external links category, and NOT remove a valid citation. Hope that explains the rational (and how you can resolve the issue in a way more suited to not undoing someone else's work in favor of your own, while still including your own input into the article).
Best,  | User Talk