Here’s page 234 of the 1976 Michael Fleisher Encyclopedia Of Comic Book Heroes Volume 1: Batman. Fleisher uses a lot of quotes and textual details in his articles.
Now, here’s page 194 of Bob Greenberger’s Essential Batman Encyclopedia, out this week.
Note that Greenberger covers the same subjects as Fleisher, includes more recent entries, and has reworked the “Joker” article to be more of an overview. It’s less detail-oriented, but reaches further.
I can’t count how many times I read Fleisher’s book as a kid, and I was very thankful to Teh EBay for my replacement copy (this was before DC reprinted it last year). However, Greenberger has done a really great job in his own right. Well worth your disposable income.