The Science Citation Index has been going for 50 years and, although I don't remember it that far back, I do remember the days of having to look up subjects in printed annual indexes (see picture), making literature searching an extremely laborious and hit-and-miss affair. The print was so small we had to keep a magnifying glass in the library to lend to users!
There are old videos showing how it used to work (see the one below for a taster), an interview with the founder Eugene Garfield, a timeline of its evolution, a podcast on the recent enhancements and more at this link. Science Citation Index 50th Anniversary page
It's now part of the Web Of Science. See what it looks like now via Birkbeck eLibrary (Bbk staff and students only)
