Source Publication (e.g., journal title)
A DECADE AGO I wrote a column called "The Most Popular Databases" (LJ 4/1/91, p. 96,98). I used data from a company called Information Market Indicators (IMI) that tracked usage in a wide sample of libraries, plus CD-ROM best sellers lists from popular computing magazines. It is harder now to track database and system usage over all types of libraries because IMI no longer collects the data, CD-ROM isn't as important in libraries, and there are now many more choices of systems and databases.
Tenopir, Carol, "Database and Online System Usage" (2001). School of Information Sciences -- Faculty Publications and Other Works.