Meredith Hale, metadata librarian at the University of Tennessee, asked on ARLIS-L if anyone could provide an authoritative source for the birth and death dates of the photographer who signed his photos Wasow. She needed the information for rights clearance and authority record creation. She noted that there are several images on Wikimedia Commons, including this portrait of art historian Heinrich Wölfflin from 1924.
Spyros Koulouris, archivist at I Tatti in Florence, responded with the link to Wasow's record in the Deutsches National Bibliothek authority file. The DNB records, as well as those of the Library of Congress, the Bibliothèque nationale de France, Getty Union List of Artist Names and several dozen other organizations, can be searched together in the Virtual International Authority File or VIAF. This is a really useful tool in name authority work.
Reflecting on this exchange on ARLIS-L, I was reminded of a little reference question I helped a fellow graduate student with, way back going on fifty years ago (early 1970s). Caroline Boyle-Turner (then Caroline Rachlis) was studying the French symbolists and was trying to verify some book by one of them. Paul Gauguin, I think. It had been elusive and she mentioned it to me. I had done plenty of searching in the book catalog of the Bibliothèque nationale when I worked on the reclassification project at Cornell University. She told me the title and we went to look in the BN catalog. I don't remember the details of the book but she was very happy to find that the book did actually exist. Catalogers can be successful reference librarians. Cataloging tools can be good sources of information. Of course, the BN book catalog, which has been supplanted at least for newer items by an online version, was not just a cataloger's resource but it wasn't on Caroline's radar. Fast forward some fifteen years or more, Caroline and I were delighted to coincide at a reception at the Van Gogh Museum in Amsterdam.
[my photo of the Van Gogh Museum from a later trip, 2016]