Here is an article from 1991 referencing Alan Kay talking about electronic books in 1971. It also describes other electronic books including this:
"Bob Stein, a partner in Voyager, said the company chose Apple's new portables because with Macintosh software it is possible to design books with animated drawings, sound effects, and so-called hypertext links, which let readers jump directly to related passages. "Apple, completely unintentionally, created the first electronic book," he said.
The first titles include "The Hitchhiker's Guide to the Galaxy," a science-fiction trilogy by Douglas Adams, "Jurassic Park," a technological thriller by Michael Crichton, and Martin Gardner's annotated version of "Alice in Wonderland." Priced at $19.95, each will come on a single floppy disk and will display one page of text at a time."
Another interesting link:
"Franklin Electronic Publishers, Inc. created the handheld electronic book category in 1986 with the introduction of the Spelling Ace electronic spelling corrector. Electronic books instantly retrieve information for viewing on a liquid crystal display. Users can access this data anywhere--at home, at the office, or while traveling. The Company offers an extensive electronic library including dictionaries and bilingual dictionaries; Bibles; medical reference works; encyclopedias; and entertainment, educational and tutorial publications."
So in 1986 Franklin was selling a device with an LCD display that presented books from ROM.
I bet some of those lawyers suing Apple were still playing street baseball when this prior art was on the market.