If a closed question is linked to other close questions, it may be helpful to make them all visible at the top of the question, instead of only showing the links from that direct question:
Homework on StackOverflow
Should I answer Homework questions?
Downvoted for answering homework!
How do we handle the questions marked homework?
Should we eliminate the homework tag?
Is the homework tag a meta tag?
There was one question someone asked about what to do if he is automatically banned from asking questions. Several close voters referenced the first question that came up in the list as the duplicate, and it happened to be closed. I had to click through three "possible duplicate" links before I reached an open question, and it even had a link to the canonical post. Here is an examplean example.
Displaying the linked duplicates may seem kind of messy, but as Joel Spolsky says, inventory that has costs and little benefit should be processed. In other words, if we see the linked duplicates list growing to an unmanageable state, that just means it's time to clean house and either delete or merge some of them.
Note that the "linked duplicates" list wouldn't show closed references, the placeholders left behind when a migration occurs. Sometimes there is value in leaving those as it does help with search results. We just don't want them appearing in our close vote lists.