It is impossible for users to work with this tool, as they cannot see the reference URLs at all.
Imported primary sources tool issue from GitHub: https://github.com/Wikidata/primarysources/issues/105
This task is a little bit vague. If the issue persists, please open a new task more detailed, thank you.
@Afnecors : it actually deals with the primary sources list, which is a sub-tool. References are not displayed there, so this ticket is relevant.