Text publications - such as scientific articles, dissertations, monographs or conference papers - are central components of scientific communication. In the digital age, however, the question increasingly arises as to how the accessibility, findability and citability of these texts can be permanently ensured.

Persistent identifiers (PIDs) offer a reliable solution here. They enable the unique and permanent identification of publications and thus contribute to making scientific content findable, citable and interoperable in the long term.

By using PIDs, researchers, publishers and infrastructure facilities benefit from

• Stable and verifiable links,
• a clear assignment of authorship,
• higher visibility of publications in search systems,
• and better integration into research information systems.

Which PIDs are used - and where are they available?

• DOI (Digital Object Identifier)
  The DOI is the most widely used PID for text publications. It is usually assigned automatically by publishers or repositories when specialist articles or other texts are published. DOI issuers include Crossref (for journal articles) and DataCite (for repositories).
• ISBN (International Standard Book Number)
  An ISBN is usually assigned to books and monographs when they are published by a publisher. This serves as a unique identifier for printed or digital book publications.
• URN (Uniform Resource Name)
  URNs are mainly used in German-speaking countries, e.g. by libraries or university publication servers. They also provide a permanent reference, often in combination with DOI or ISBN.

Consistent use of these identifiers promotes a reliable and sustainable research infrastructure in which scientific texts can be found and correctly referenced in the long term.

In September 2023, a workshop on PIDs in text publications was held as part of the project at the Open Access Days in Berlin. The documentation is available here: https://doi.org/10.5281/zenodo.10522511