Scientific publications (but not only restricted to) usually follow this format:

• There is a "Journal" (this type already exists for "Publications").
• A Journal has different "Volumes" (these could, at the current state of the database be added as "Editions", with the drawback of the next point).
• A Volume of a Journal has different "Issues" (not clear how do this with the current database structure)
• Within an Issue there are multiple "Articles" ("Article" as Publication type is missing)

So, I would suggest the following improvement:
Add "Volume", "Issue", and "Article" as Publication types
Furthermore, add ISSN fields for "Journals". A "Journal" comes often with an ISSN ("The ISSN is the international standardized code which identifies all serials, journals, magazines, periodicals irrespective of their medium (print or electronic)", see www.issn.org).
Finally, add DOI fields for "Issues" and "Articles". "Issues" and "Articles" often have a DOI ("Digital Object Identifier", see www.doi.org).
As a next step: Articles often appear as preprint (also called eprint) before a final publication. Preprints are put online on websites like www.arxiv.com and https://eprint.iacr.org/. Thus, one could add these preprint identifiers as well.

I would happy to contribute — in coding as well — to these improvements. Please let me know where and how I could do that.

Thanks