You can make the Added column visible in the Bookmarks Manager (Library) via the right-click context menu on the header or the Views menu (Views -> Show Columns), so If you remember when you created this bookmark then you can search for bookmarks created around this time.

Thank you cor-el, for taking the time to read and respond. Unfortunately, I do not know when I first created this list of bookmarks of book reviews and book lists.

Are you saying the title of the bookmark matches the pattern book*.* or the URL of the page you bookmarked matches book*.* or you bookmarked a local file whose name matches book*.* ?

Thanks for the reply. I don't believe I ever bookmarked a local file. I think it must have been a URL with name in that pattern.

Okay, the search syntax doesn't support wildcards in that way, so taking a different approach, try search in the Bookmarks Sidebar (Ctrl+b) or in the Library (Ctrl+Shift+o as in "Organizer") for this pattern

/book

That should match any part of the url where book immediately follows a forward slash.

Any luck?

Very helpful suggestion, however it did not turn up that for which I was looking. I am afraid I inadvertently deleted my folder with the bunch of bookmarked URLs collected over the years featuring reviews or lists of books in which I was interested.

Very sad for this librarian.  : (

Thank you once again.

If you can remember any of the titles, that might help. You also can export the bookmarks to an HTML file and search that in a tab or in your favorite word processor.

Export Firefox bookmarks to an HTML file to back up or transfer bookmarks