Volumes dedicated to a single topic have been released, under the title "Uncle John Plunges Into...", for example: history, presidents, and the universe. There are also books on individual U.S. states, the weather, numbers, quotes, the year 2000, a special book for mothers, cat lovers, dog lovers, horse lovers, love, "Uncle John's Book of the Dumb", and several "Bathroom Readers for Kids Only!". Though most of the books were written by the Bathroom Readers' Institute, some of the ones that are based around a specific subject are written by a lone author, who is not in the Institute. Additionally, the Institute will often publish articles and other contributions sent in from readers. Recurring articles such as "Flubbed Headlines", "Oops", and "Classifieds" often depend on these contributions. Currently, the institute publishes three books a year; a "classic" reader, and two "plunges into" editions, one for a location such as a U.S. state, and another of a specific topic.