Needed to find a 30-year-old paper at the library yesterday, from a reference to "C.R. Acad. Sci. Paris". Fortunately, I remembered what C.R. stood for, but couldn't remember offhand whether the next words would be du or de l'... eventually I just entered "Comptes Rendus" in the catalog, and scanned through the seven pages of results to find one that looked right, Comptes Rendus de l'Académie des Sciences. Or rather, many that looked right, because that name belonged to many different series, none of which seemed to match the one in the citation I was searching for. I almost decided that this meant our library didn't have what I wanted and started to prepare an interlibrary loan request, until I realized that the closest matching entry had a pointer to a previous C.R. series that it continued under a different name. Half a dozen name-change backpointers later, I finally found Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences, with the correct series, from which I found the call numbers to locate it in the stacks. Where all the C.R.s were shelved together, under the same call number, so I again had to scan sequentially through them to locate the correct series again.

From which I conclude that there's a lot to be said for on-line full-text journal archives, and services like ACM Portal and Google Scholar that index them, despite their impermanence compared to paper.

Also that precision and usability are to some extent conflicting goals in bibliography. I mean, who cares whether the word "Hebdomadaires" was in the journal name for some years and not for other years, just let me know where I can find my papers.