Over 5000 titles of books printed in the sixteenth and seventeenth centuries from the collection of the Academy Library in Cluj are now inventoried by the Universal Short Title Catalogue. On the initiative of Prof. Adrian Papahagi, several students from the Babeș-Bolyai University compiled a concordance of library shelfmarks and USTC call numbers, thus putting the Academy Library on the map. Most entries were contributed by David Mândruț, PhD student.
Some copies are extremely rare, and are attested only in Cluj. Here is an example:

“The Universal Short Title Catalogue (USTC), developed at and hosted by the University of St Andrews, is a collective catalogue of all the books published in Europe and its overseas colonies between the invention of printing and 1700. It is a free to access resource, that can be used anywhere in the world.
It currently contains bibliographical descriptions of more than 1.6 million editions published between 1450 and 1700, located in almost 7 million surviving copies in close to 10,000 libraries, archives and museums throughout the world.”
See p. 4 of the USTC Library Quarterly 13 (August 2026).