From my testing, searching for
"domain1.com/article1" OR "domain2.org/article2" OR "domain3.net/article3" (including quotes, uppercase OR) seems to work.
Twitter appears to expand shortened URLs within tweets so you needn’t worry about handling those cases.
You should then be able to setup an If-This-Then-That Applet to send you an alert through the medium of your choice (email, SMS, in-app notification…) whenever a new tweet matches your criterion.
Twitter’s Help Document doesn’t specify whether there is a character limit on searches, but I imagine sooner or later you’ll need to split up your query. In the meantime, you may omit any prefix and subdomain, and only retain the parts that uniquely identify your pages.
It’s worth mentioning that starting sometime in December 2016, you can no longer insert
TweetEmbedCode into emails sent to an iCloud address.