There is a function called "Linked" which should show all the linked questions, the problem is that it shows too those questions that somewhere in the post or comments has a link to a post... so, there are super-referenced questions that you get lots of non-duplicates. The only solution is using a query:
This query will find all post that links to How to fix Duplicate sources.list entry? and any other ID you like. I presume you know how to find the ID, but just in case
The query is thanks to animuson's Find duplicates of deleted posts which share lots of stuff.