PhycoBank

Registrations are naturally bundled into working sets by the Reference entity for the related publications.

A single publication can encompass several new names and typedesignations. For each of the names and typedesignations an individual identifier and thus a separate registration is needed.
For better user experience registrations forming a working set should be bundled in the UI in order to reduce redundancy in the visual appearance and in the users efforts to process through the registration workflow.

A Registration is indirectly associated with the publication Reference by the following paths along the object graph:

Registration -+---> name ---> nomenclaturalReference
              |
              +---> typeDesignations ---> citation

I think it is OK to collect the References using this relationships so that it is not needed to add a private Reference publication; field to the Registration class.
The purpose of this ticket is to let you know about the requirement to use the workingsets and to start the discussion if needed.